Fix: Xcode 5 recommended settings

* Select architectures based on deployment target
* Use current architecture for Debug build
* Enable recommended warnings
Remove executable flags from source files
Merge pull request #169 from nanoant/patch/fix-xcode5-warnings

Patch/fix xcode5 warnings
Removing the workspace .xccheckout file.

This file does not make much sense for this project see http://stackoverflow.com/questions/18340453/should-xccheckout-files-in-xcode5-be-ignored-under-vcs
Replacing roundf() with round() from thmath.h. 

Improves 64 bit compatibility. See http://stackoverflow.com/questions/7694948/cgfloat-round-floor-abs-and-32-64-bit-precision
fix arm 64 compiling error
Merge pull request #186 from holyman2k/master

fix arm 64 compiling error
Update MBProgressHUD.m

Cancel scheduled task when -done called to fix memory issues.
Merge pull request #192 from liuyaodong/patch-1

Canceling scheduled method calls inside `done`.
Add Xcode suggested GCC_WARN_64_TO_32_BIT_CONVERSION warning to Demo project
Merge pull request #199 from rivera-ernesto/add_suggested_warning_check

Add Xcode suggested GCC_WARN_64_TO_32_BIT_CONVERSION warning to Demo project
Comment cleanup / fix. #201