setMultipartFile improvements

Add optional content-type header.
Automatically detect content-type.
Fix NPE when setting after calling configure().userAgent(String).
Add setMultipartParameters method.
Use weak references on cache eviction.
Fix up crash around weak ref usage

Change-Id: If074d75e410a2db1391654d48069e5381ffa9823
Fix up crash around weak ref usage

Change-Id: I45198f1b3ba4ad5a657f323aa322f0ac3808d6d4
Do not use weak refs on gifs, as only one bitmap
is ever held at a time.

Change-Id: Ibdf97fa98c551109327df67aea47f672b443b0cb
TODO: make ion hold a reference to all the bitmaps?
The weak ref stuff is totally broken. Comment it out.

Change-Id: Ic19b9dfcbf92f623bfe31e8b38e66836cd9958f9
Add dynamic cache size adjustments.
Send resize width/height header as hints.

Change-Id: I96dea2c65bed4635c54899cf4234cf7320cfeef3
Merge remote-tracking branch 'koush/master' into cm-11.0
herp derp

Change-Id: Ic7dc0d19ab6f58f3ab2d38fd08c364a57073d5c5
Update README.md

For those that want to live on the bleeding edge and aren't familiar with how to build it like me.
Merge pull request #114 from Krayzk9s/patch-1

Update README.md
Merge branch 'koush-authority/master'

Conflicts:
	ion/src/com/koushikdutta/ion/bitmap/LruBitmapCache.java