Major update for crash reporting

- UI is not shown modal any longer! If you app crashes early, you need to check this yourself and delay as much of your code as possible until the crash report was successfully sent
- Removed `showMainApplicationWindowForCrashManager:` delegate
- Added option to show your own custom user interface, see `setCrashReportUIHandler` and `handleUserInput:withUserProvidedMetaData:`
- Added details about the crash in the last app session, see `lastSessionCrashDetails`
- Added option to add a binary attachment to each crash report
- Added `setCrashCallbacks` to execute your own async-safe code right after a crash
- Send  each crash report individually
- More code unification with iOS SDK
Adopt BITHockeyManager to use BITHockeyAppClient and remove 10.5 specific code
Instead of removing the delegate `showMainApplicationWindowForCrashManager:` mark it as deprecated with an appropriate message
Make sure checking for non approved crash reports also works when there is no crash in the last session
Fix handling of some edge cases in relation to sending approved crash reports
Removing now unused property
Move getting SDK dir into Helper
Move BITCrashAttachment to BITHockeyAttachment

- More general approach
- Add some safeguards
Update Feedback UI

- Now requires OS X 10.7 minimum
- Modernized components (no more NSCell, ...)
Change CrashReport UI nib to xib
Make Feedback UI localizable
Fix an exception and weird issue
Better feedback list view divider
More polish

- Users text shown right aligned and white background
- Spacing between cells should be 0
Always show time
Begin feedback attachment support

Not working yet
Convert to ARC
More work on feedback attachments

- Preview as thumbnail in list view
- Use Quick Look for full size view
More feedback attachment stuff

- Drag & Drop attachment onto compose view
- View attachments in a list next to the compose view
- Options to preview and remove attachments from the list
Minor heade file updates