Improved performance and buildtime for code.o

(disabled stack canaries)
Updated Makefile

* No deleting Codegen until 'make clean'
* Reuse Codegen binary when possible
Merge branch 'hotfix-stoke-24'
Berkeley needs to access the buffer in each function for his experiments.
Bugfix. See stoke issue 29. gcc prints out negative mem offsets using
negative hex notation. Syncing with that behavior. Also, printing code
in tools/x64asm.cc
Merge branch 'hotfix-stoke-29'
I claim intel manual is wrong for lddqu
I think I've done what's needed, not tested yet.
fixed typo; is_call -> is_call_
is_call now works.  Tested in my stoke branch.
Merge branch 'feature-23' of github.com:eschkufz/x64asm into feature-23
Overloaded stream operator for RegSet.  Inefficient.
Added some new regset constants
fixed typo
Replaced Unicode non-ASCII codepoints from x86.csv; these caused parsing to fail on Ubuntu 13.10 with default package versions.
This is a branch corresponding to pull request #24.
Merge branch 'hotfix-24' into develop