- Changed expand wildcard behavior.
- Fixed expand glob.
- Fixed backquote.
- Improved glob().
add android support

The implementation for android uses ptytty.c like sunos because Android
NDK does not have libutil. But in ptytty.c, 'STREAMS modules pushing' is
not supported in Android and seems to be not needed, therefore I disable
it for Android.
And in proc.c, Android does not support WIFCONTINUED, it uses WIFSTOPPED
and WSTOPSIG instead.

NOTICE:
Some environment variables are needed for make. This notice is also
written in make_android.mak with an example.
Merge pull request #43 from rusuki/add_android_support

add android support
- Added Android support.
- Fixed escape sequence behavior.
- Fixed for double quote.
- Improved catch behavior.
- Improved tests.
Conpensated the initializer and the terminator of the Winsock in vp_host_exists().
Lelated the issue #44.
Merge pull request #45 from AmaiSaeta/fix/vp_host_exists-missing-init-4-winsock

Conpensated the initializer and the terminator of the Winsock in vp_host_exists().
Modularized the initializing and the terminating process of the Winsock.
Added the Winsock initialization/termination failure processes.
Merge pull request #46 from AmaiSaeta/refactoring/submodulize-winsock-initializer-terminator

Modularized the initializing and the terminating process of the Winsock.
- Fixed vimproc#system_passwd().
- Fixed vimproc#system_passwd().
Improved doc.
Merge pull request #47 from crazymaster/master

Improved doc.