Fix make distcheck.

Having a nested directory in top-level automake SUBDIRS caused
the directory to be build, but not dist-ed, so the 'make distcheck'
test would fail because it couldn't find src/tests/Makefile.in.

Instead, recurse according the the directory tree. We have to
put the current directory first in src/Makefile.am to ensure
it's built before the tests when depend on them.
Move jenkins build scripts into the tree.

This just does the unix and autotools builds, scan-build and
coverage still need to be fixed up and moved.

Having these in the tree makes the tests more transparent,
and something which can be run locally, instead of having
that part of the configuration tied up in the jenkins database.
Change OP_ prefixes to OD_.
Make is now non-recursive.
Fix make distcheck.
Better encoding for the block size decisions

The decision on how to split 16x16 blocks now uses the full context of the
5 neighbouring 8x8 decisions on the top, topleft, and left.
Merge branch 'switch_encoding'
Proper split of the block size encoding and decoding functions
Fix the buffer size in od_intra_pred16x16_dist().

Thanks to Aroeht for the patch.
Move macroblock encoding out to prepare for block size switching.
Fix missing math library linking.
Fix warnings.
Clean up merge conflicts from a5ce5af6.
Merge remote-tracking branch 'jack/autofixes'

Had to disable mc.pdf from the build
Conflicts:
	src/Makefile.am
	tools/Makefile.am
Update unix makefile for source directory changes.

Add new files and re-arrange things to match Makefile.am.
Fixed build
Fixed build nits
Header encoding (mostly untested).

Reviewed at: https://daala-codereview.appspot.com/2001/