Development section: added a dependency and the command to switch in the dev branch

In the development section, added instruction for Linux Mint Debian Edition dependencies' problems and the switch to the develop branch of the repo
INSTALL: Fixed the previous commit

Merged with the lines by @azul so now the text is more generic and suitable for different situations.
Merge pull request #103 from tubia/master

Development section: added a dependency and the command to switch in the...