Fixed compilation with python bindings
Fixed syntax error

Damn you remote editing...
Added option to build with brewed python

Since python is installed by default, let's always build bindings for it.
But if a brewed python is installed, allow its usage through option.
Proper handling of system python vs. brewed python
Make sure to link with boost_python-mt
libtorrent-rasterbar: add 0.16.15 bottle.