Moved ycmd-related files to third_party/ycmd

This is in preparation of splitting ycmd into a separate project.
Updating code to work with new ycmd location
Moving cpp code to ycmd folder
Updated CMakeLists to place libs in ycmd folder
Error message for old location libs
Shell scripts now use new ycmd location
build/test scripts split into ycmd/ycm versions
Moving ycmd deps to ycmd/third_party
More fixes for separate ycmd
Now importing ycmd's third_party folders as well
ycm tests now add ycmd/third_party to PYTHONPATH