Emacs: configure irony and semantic pkgs
Emacs: configure irony and semantic pkgs

Configure irony and semantic pkgs and configure these as company
backends.

Need to install libclang-dev and friends for irony mode to work.
After initial install run M-x irony-install-server to install
irony-server

Signed-off-by: Ratheesh S <a1e9b1f7f1fd346c2fcd33571191e12a4dbe637a@mistralsolutions.com>
Tested-by: Ratheesh S <a1e9b1f7f1fd346c2fcd33571191e12a4dbe637a@mistralsolutions.com>

ratheesh/dot-files,ratheesh/dot-files