unit test objects added.
replace values in NSDictionary to NSString
add PIXAlbumTests
int value validation method added.
int value validation method added.
fix method description.
fix some method descriptions.
get album set comments bug fix
mark album set comment as spam or ham methods added.
mark album set comment as spam or ham methods added in PIXNETSDK
mile stone~~
set constants for unit test
commit for v0.3
Merge branch 'master' of github.com:pixnet/pixnet-ios-sdk