More on gcc

* link to the PPA
* PPA is the light & the way...but direct to build tips just in case
Merge pull request #95 from vmbrasseur/master

More on gcc
Recommended space for a gcc build

A gcc build needs > 3.5GB space. Guess how I learned that?
Link to a different gcc PPA

This one includes the required version of binutils.

Also, include g++ 4.8.2 in the list of required compilers.
Merge pull request #96 from vmbrasseur/master

gcc tweaks
Change Quick Start to be Ubuntu-specific

The "look below & install pre-reqs then come back here"-ness of it was
bugging me.

As the most currently most popular distro, just default this quick
start to Ubuntu. Add lines for getting gcc/g++, pre-reqs.
Merge pull request #97 from vmbrasseur/master

Change Quick Start to be Ubuntu-specific