Stability fixes and performance improvements

- Removes dependencies except for FMDB
- Renames insertObject to addObject to adhere to Cocoa standards
- Ensures BAPersistentOperation delegate methods are performed in main
thread
- Closes db after using it
- Updates podspec
Merge pull request #8 from inf0rmer/stability-fixes

Stability fixes and performance improvements
Prepares example interface
Implements simple example without queue
Finished working example