Add manual ffmpeg path support to cmake

This commit adds support for allowing the user to define the full
path to the static ffmpeg libraries.

In addition it also makes cmake output the location for the
static ffmpeg libraries that it will use.
Add dummy sceCcc

Fix loading of Gensou Chronicle
Correct sceMpegAvcDecode/sceMpegAvcDecodeYCbCr behavior.
Fix typo
Merge pull request #2558 from oioitff/mpeg-fix

Correct sceMpegAvcDecode/sceMpegAvcDecodeYCbCr behavior.
Merge pull request #2557 from sum2012/sceccc-patch

Add dummy sceCcc
Merge pull request #2556 from Kingcom/master

Memory view in disassembler
Keep the symbol map entries unique.

Duplicates are annoying, and we have hacks upstream to prevent them that
cause trouble.
Always add symbols, so we don't leave any behind.
Keep symbols mapped from all loaded modules.

This way the map contains all the symbols used, not just a snapshot.
Read symbols with spaces in their names.

Before it was changing "UNK: hex" and "EXP: hex" into "UNK:" and "EXP:".
Add a couple extra stubs to sceCcc.
Add some unknown syscalls from reporting.

These are being linked in by games, so defining them will log them when
they are hit.
Merge pull request #2560 from unknownbrackets/symbol-map

Keep symbol map entries from between modules
Merge pull request #2561 from unknownbrackets/ccc

Add a hack/stub for sceCccUTF8toSJIS(), some other stubs
Improve getPsmf for scePsmf.
delete previous psmf if exists.
Log more info about branches in delay slots.
Merge pull request #2562 from oioitff/mpeg-fix

Improve getPsmf for scePsmf.
Tiny bug fix for scePsmfSetPsmf.