adapt the adjustment limit for rate correction factor in RTC mode

Rate correction factor is used to correct the estimated rate for any
given quantizer, and feeds into rate control for quantizer selection.
We make use of the actual bits used to calculate this rate correction
factor with an adjustment limit to prevent over-adjustment.

This commit adapts the adjustment limit to the difference between the
estimated bits and the actual bits, allows the adjustment limit to vary
between 0.125 (when estimate is close to actual) and 0.625 (when there
is >10X factor off between estimated and actual bits). By doing this,
the commit appears to have largely corrected two observed issues:
1. Adjustment is too slow when the actual bits used is way off from
estimate due to the small adjustment limit.
2. Extreme oscillating quantizer choices due to the feedback loop.

Change-Id: I4ee148d2c9d26d173b6c48011313ddb07ce2d7d6
Revert "Fix SSSE3 partial_idct_test detection"

This reverts commit 7d07f512cd87446eef541e9af4af19b1e8c6342a.

this breaks visual studio builds:
'#' : invalid character : possibly the result of a macro expansion

Change-Id: I77170d549afb71e75a878fa0f6acd204fe8d9e67
Fix 32 bit build emms problem.

Add extra vp9_clear_system_state() calls to fix
double / mmx issue introduced into first pass
code for 32 bit builds.

Change-Id: I84cd2986b80d83650a091ab25c43755efeb82e03
Prepare for dynamic frame resizing in the recode loop

Prepare for the introduction of frame-size change
logic into the recode loop.

Separated the speed dependent features into
separate static and dynamic parts, the latter being
those features that are dependent on the frame size.

Change-Id: Ia693e28c5cf069a1a7bf12e49ecf83e440e1d313
Merge "Revert "Fix SSSE3 partial_idct_test detection""
Merge "Fix 32 bit build emms problem."
Merge "Prepare for dynamic frame resizing in the recode loop"
Merge "adapt the adjustment limit for rate correction factor in RTC mode"