Removed setCallbackUserData calls from the last few newview files
Upload code cleansing

I found our upload classes were in need of a tune up while researching Issue 896: Animation upload setting causes viewer crash
So I started working to clean up llfloaterbvhpreview which lead me to llfloaternamedesc and the rest of our upload floaters
I ended up pulling the sound upload hack out of LLFloaterNameDesc and into LLFloaterSoundPreview and moving LLFloaterAnimPreview into llfloaternamedesc.*
Updated llviewermenufile.cpp a bit
Removed setUploadAmount from LLFloaterImagePreview and LLFloaterBvhPreview as its purpose is served by LLGlobalEconomy::getPriceUpload and the hippogridmanager too.
Fixed an issue with floater_animation_anim_preview.xml using [AMOUNT] instead of [UPLOADFEE] for its label.

I'd say this might fix Issue 896, I certainly can't reproduce the crash I was having when testing for it anymore.
Some minor tweaks to llfloaterpostprocess

Just to make it a little nicer and cleaner, a few changes are from upstream.
Update LLFloaterWater and LLFloaterWindLight, to be closer to their upstream counterparts.
And finally, update the callbacks on the last few panels to use boost

Cleans up LLPanelSkins enough to remove sInstance hack.
Modernizes some callbacks on wlfPanel
Remove mCommitCallback, mValidateCallback, and mCallbackUserData and related functions from LLUICtrl and derived classes