made btsend a git submodule instead
(http://git-scm.com/book/en/v2/Git-Tools-Submodules)
this way, if there is an update in my repository we can automatically download
the new code for btsend by updating the submodule.
Doing so would look like this (to update btsend) in a terminal:

git submodule update --remote btsend/
cd btsend
git checkout master
git merge FETCH_HEAD

OR the alternative (I think this is way more simple):

cd btsend
git pull
echo -e "submodule\x73\x20a\x72e c\x6F\x6f\x6c"