Adds new Makefile target to add package to the latex default path
Adds missing MINI-HOWTO-prosper.txt file

Source: https://github.com/fcecagno/masters-ti/blob/master/MINI-HOWTO-prosper.txt

MINI-HOWTO-prosper.txt describes how one can use the "prosper" class to create
presentations.

The described procedure was NOT tested, so I'm not sure if it is up-to-date.
Standardizes README encoding to UTF-8
Removes obsolete prosper how-to
Changes the default install directory

Changes the default install directory to the user latex packages directory
($HOME/texmf/tex/latex/iiufrgs), so there is no need to use sudo or regenerate
the ls-R databases when installing.
Merge pull request #3 from tcsantini/doc_and_install

Doc and install