add log message MOAI_FileOpenError_S

While this may seem redundant with MOAI_FileNotFound_S, there
may be cases where the file exists but can't be opened, e.g.,
due to permission errors. This also supports a safer code structure:
actually try to open the file and log if it fails, instead of checking
for file existence and then just assuming it will open.
use MOAILogMessages::CheckFileExists instead of USFileSys::CheckFileExists so we get an error message
Log if file didn't open successfully
check and log if sound file doesn't exist

I would have preferred to check whether the actual file-open
operation succeeded, but this would require adding a check inside
untz itself, which doesn't have a clear logging mechanism at
the moment.
- Camera support for iOS on moai
- Fixed not dimissing picker
fix Animation Error

fix Error: last Frame in MOAIAnim2D not readed
custom Build Files for MAC

no Facebook, Tabjoy and Fmod
add MAC Binarys
Revert "add MAC Binarys"

This reverts commit cb39d560446c3e8eba0648d7643f75884248eb6b.
Revert "custom Build Files for MAC"

This reverts commit 4cc6c3c6bc66c63ece69f01b1da6151709a36e74.
updated box2d physics sample

adding mouse manipulation using mouse joint
Added support for collideConnected flag to MOAIBox2DWorld::_addRopeJoint

Distance joints support the collideConnected flag already, but rope
joints do not.
fix edge case that new-created-paused action cannot receive further update
Adding file not found log if a texture file fails to load
Fixing build errors for DataTaskIO
fix: MOAIImageTexture not override OnInvalidate
Merge pull request #619 from antback/master

Initial Camera Support for iOS
Merge pull request #618 from tommo/bug-fix

fix: MOAIImageTexture not override OnInvalidate
Merge pull request #592 from sporksmith/log-file-open-fails-pull-req

Log file-open failures