Merge pull request #17 from caiywHub/feature_1

add api: xtime/xdebug/xfile，缺少xtime的部分实现
fix xC.pro/xdebug/xfile
Merge pull request #22 from guangbin79/fix_api

fix xC.pro/xdebug/xfile
fix compile warnings
Merge pull request #23 from guangbin79/fix_api

fix compile warnings
add api xmemory/ximage/xtimer
Merge pull request #25 from mgya/wangxt

add api xmemory/ximage/xtimer
xfont / xgl / xopengl -- impl.
Merge pull request #14 from tangbo2013/develop

impl xopengl.h / xgl.h / xfont.h
 add api: xrand/xtapi
Merge pull request #21 from gaolele5911/xtapiAndxrand2

merge xtapi and xrand2.
add time function