Set Psmf->headerSize to something.

Before it was uninitialized.
Load the EP map from the psmf data when available.

Rather than just having uninitialized values.

Fixes #2642, World Neverland.
Fix typo.
Merge pull request #4965 from unknownbrackets/psmf-epmap

Try to properly load the psmf EP map
Set cleardepth the traditional way on desktop.
Possible Qt buildfix
Get rid of "ATIClampBug", it's not a bug, it's just lack of full non-pow-2 texture support
Initialize m_decodingsize to 0.

Fixes #4609, intermittent video issues in Lunar.
_PsmfPlayerFillRingbuffer() expects getRemainSize() to return something
useful even before the context is opened.
Merge pull request #4966 from unknownbrackets/psmf-minor

Initialize m_decodingsize to 0
Add ini options to configure the texture cache.
Fix #4922, kill age checks in texcache.
Cleanup differences in DirectX9 texcache code.
Add UI options for new texcache options.
Default off the texture cache options.

They cause noticeable glitches in a bunch of games.  The speed improvement
in some games is very good, but in quite a few it is small.