dealii 8.2 (new formula)

Added a formula to install dealii from GitHub.
Head points to master branch,
whereas devel shows an example of how to compile from
the local Git repository.
Note that in either case the sources are cached in Library/Caches/Homebrew/dealii*
dealii 8.2 (update)

fix error with the wrong CMake path
when installing the release version.
Dealii 8.2 (FIX)

Specified additional CMake parameter to change the
directory structure.
deal.II 8.2. (update)

add the following:
* optional usage of the bundled boost
* default parameters to the dependencies
* enforce Cmake to autodetect libraries within Homebrew prefix only
Merge branch 'dealii'

Conflicts:
	dealii.rb