gitignore: update gitignores file from github gitignore repo

Change-Id: I22d5b87560bfefc1ec1e5fa20dac8fb2ba980beb
Reviewed-on: http://gerrit.lokigoma.net/53
Reviewed-by: Pierre-Alexandre Goya <pierre.alexandre.goya@gmail.com>
remove poc folder

Change-Id: I3c7292891ca0d8b95a3a8c64b4db0af7732b166e
Reviewed-on: http://gerrit.lokigoma.net/54
Reviewed-by: Pierre-Alexandre Goya <pierre.alexandre.goya@gmail.com>