2bwm + cwm

Hi xtraemo,
Two new WMs in our repo. About 2bwm, it was a bit tricky. I added <code>sed -i '/#include <stdlib.h>/i#define _GNU_SOURCE' 2bwm.c</code> because it removes a warning <code>warning: implicit declaration of function `asprintf'</code>.
I didn't use the provided Makefile (because it fails).
Cross-builds are OK.

cwm:
```
./props.plist
./files.plist
./usr/bin/cwm
./usr/share/man/man5/cwmrc.5.gz
./usr/share/man/man1/cwm.1.gz
```

2bwm:
```
./props.plist
./files.plist
./usr/bin/hidden
./usr/bin/2bwm
./usr/share/man/man1/2bwm.1.gz
./usr/share/man/man1/hidden.1.gz
./usr/share/doc/2bwm-git/README.md
```
Cheers.