Adds a 'libvpx' target used to build the (soon to be added) jnvpx library. Reverts the instruction for building the jnffmpeg library, since libvpx won't have to be compiled into it anymore.

git-svn-id: https://svn.java.net/svn/jitsi~svn/libjitsi@10332 198c5059-ef06-4ec0-9a75-fdd6b0ef00a6
Merge Metaswitch fixes

r615
Stop stack traces being logged when write() is called without a target (which can be valid, according to comments) as log files are getting spammed.
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r595
Code review mark-ups for improved config logging.
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r509
Correction to r508: imports shouldn't be corrected from * change logging level of config changes to INFO
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r508
Add logging of the initial config on startup, and all changes
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r446
Reduce maximum resolution and framerate to allow interop with the mobile client.
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Log the first second of media and then one packet per second after that.
Commiting proposed fix to bug 452 to temporary branch to create a patch for code review.
Add some logging from TJLP for bug #250
Add missing import
Add some logging from TJLP for bug #250
Add missing import
Add logging to AudioMixer so we can see why on no-way media calls we get on one call to addInputDataSource
Add some logging from TJLP for bug #250
Add missing import
Add some logging from TJLP for bug #250
Add missing import
Fix up merge problems
Add some logging from TJLP for bug #250
Add missing import
Add some logging from TJLP for bug #250
Add missing import
Add syncrhonized keyword to make sure we don't create two processors and choose the wrong one when setting up calls.

This problem is hit most frequently when there is early media and a rapid reinvite and it can result in no RTP being sent.

NOTE: I've not been able to fully test this fix.