Enable additional keys, remove lock files, fix clipboard under WSL, reduce binary size

[TobiasKarnat]

No description provided.

[TobiasKarnat]

I have now additionally removed dead code and fixed almost all compiler warnings.
But I'm unsure how to solve the -Wsign-compare warnings, can you have a look (with -Wextra)?

gcs.c: In function ‘_getfillgc2’:
gcs.c:241:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(val == ~0)
                    ^~
gcs.c:247:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(val == ~0)
                    ^~
gcs.c:254:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(val == ~0)
                    ^~
frptofchar.c: In function ‘_frptofcharptb’:
frptofchar.c:16:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(p < (l=NRUNE(b))){
              ^
cmd.c: In function ‘inputc’:
cmd.c:113:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (r == WEOF && errno == EILSEQ){
               ^~
file.c: In function ‘Fupdate’:
file.c:341:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(p0 > f->markp+sizeof(Posn)/RUNESIZE){    /* for undo, this throws away the undo transcript */
           ^
io.c: In function ‘writef’:
io.c:50:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             (f->dev!=dev || f->qid!=qid || f->date<mtime)){
                    ^~
io.c:50:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             (f->dev!=dev || f->qid!=qid || f->date<mtime)){
                                   ^~
io.c: In function ‘readio’:
io.c:94:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (buf[0] == WEOF){
                    ^~
regexp.c: In function ‘classmatch’:
regexp.c:517:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(*p == 0xFFFFFFFF){
               ^~
string.c: In function ‘Strinsure’:
string.c:70:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(p->size < n){    /* p needs to grow */
                ^
sys.c: In function ‘Write’:
sys.c:39:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (m != n)
           ^~
menu.c: In function ‘genmenu3’:
menu.c:383:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(i<mw && k<sizeof buf-1){
                    ^
mesg.c: In function ‘outlong’:
mesg.c:464:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i = 0; i < sizeof(buf); i++, l >>= 8)
                  ^
rasp.c: In function ‘rload’:
rasp.c:184:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(p=0,s=r->sect; s && p+s->nrunes<=p0; s=s->next)
                                        ^~
rasp.c:186:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(p<p1 && s){
            ^
rasp.c:195:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(n>p1-p0) /* all in this section */
                 ^
rasp.c: In function ‘rmissing’:
rasp.c:217:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(p=0,s=r->sect; s && p+s->nrunes<=p0; s=s->next)
                                        ^~
rasp.c:219:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(p<p1 && s){
            ^
rasp.c:222:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(n > p1-p0)   /* all in this section */
                  ^
rasp.c: In function ‘rcontig’:
rasp.c:240:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(p=0,s=r->sect; s && p+s->nrunes<=p0; s=s->next)
                                        ^~
rasp.c:242:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(p<p1 && s && (text ? (s->text!=0) : (s->text==0))){
            ^
rasp.c:244:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(n > p1-p0)   /* all in this section */
              ^