use clang to build libav

- Clang is the future on OS X and it gives more
  informative error messages.
Build libav against OS X 10.7

- This isn't strictly necessary but I'm making this change for
  two reasons?:
  1) I don't have the 10.6 SDK installed on my main development
  machine.
  2) Movist is going to require it shortly as I switch from
  Quicktime to AV Foundation (because some QT functions Movist
  uses won't ever be 64-bit and AV Foundation is the future)
Move to libav 0.8.3

- Also bumpped the guard file number to force a rebuild.
Add insertURLs:atIndex: method to Playlist

- So we can use it in place of insertFiles: where it's
  being used with the deprecated "filenames" method
  of NSOpenPanel.
Fix return type mismatch warning

- the compare function is supposed to return an
  NSInteger.
Replace use of deprecated function

- Silences a warning
Fix method arg type definition mismatch

- These methods take NSInteger types and not plain
  integer types.
- This fixes a warning.
Add cast to fix warning

- Since the method returns an id the compiler doesn't know
  which class' "set" method we want to call.
Remove old carbon windowing code

- The code looks like it's trying to make the window hidden
  when using expose but it actually appears that there's
  a bug in the code that sets this property and then
  promptly unsets it. I've never really used this so I'm
  only guessing at what it was supposed to do (if it
  even worked at all). Fortunately it looks like
  (according to the docs) the setting of the window level
  to non-normal it supposedly achieves the desired effect.
  Although by comparing the documentation it appears that
  what we really want is a combination of:
  NSWindowCollectionBehaviorTransient
  and NSWindowCollectionBehaviorCanJoinAllSpaces.
Fix format string type warning

- NSInteger changes size depending on the architecture
  and %d is always expecting a 32-bit int.
Fix types used for malloc

- NSIndexSet operates on NSUIntegers and not plain
  unsigned ints. Yikes! This should be switched away
  from malloc and to a block enumerator.
Fix argument type mismatch warning

- another integer/NSInteger mismatch.
Add needed header file import

- Won't compile without it.
Remove redundant class method definition

- This exact same method in this same class is
  already defined elsewhere.
- Fixes a warning.
Remove reference to now non-existant pixel format

- We're using libswscale so we probably don't even need this
  whole file. I'm just trying to get things working though
  so I'm not going to remove it yet.
- Wow these pixel formats are from QuickDraw?! Yikes.
Fix use of deprecated runModalForTypes: usage

- Fixes some warnings.
Remove use of NSOpenPanel filename methods

- Fixes some warnings.
Fix use of deprecated drawImage:atPoint:fromRect

- Fixes some warnings.
Replace use of deprecated ComponentManager functions

- Fixes some warnings.
Fix arg type declaration mismatch

- Now that we're trying to compile 64-bit these differences
  are significant.
- Fixes a warning.