Refactor the classes for quantum mechanics

Split the core quantum classes into several, using Core::BasisSet as the
core data container, with Core::GaussianSet and Core::SlaterSet as the
derived types. Added a Core::GaussianSetTools to provide tools to
calculate properties such as molecular orbital values. Moved the
QtConcurrent based code into the quantum plugin to perform parallel
calculations of cubes (in much the same way as before) for molecular
orbitals and electron densities.

Ported the GAMESS-US, Gaussian and Molden readers to use the
Io::FileFormat base class, and removed the Qt dependecy from them. The
others will follow, using the same deign. This removes the need for the
BasisSetLoader class, and adds several enhancements to the GAMESS and
Gaussian parsers. They both need more work (and some example files) in
order to handle open shell calculations correctly.

This currently reads in the SlaterSet from the MOPAC AUX file, but the
cube calculation duplicates the GaussianSetTools class currently. The
proted code appears to work, but there is a need to validate the
calculated results against known base lines (this was true for the
previous versions of the code too).

Change-Id: Id05e60fef70e1af18f931880c2322f33e0049187
API changes to fit with Avogadro style

Change-Id: Ic5ab2913862f70cdc546fc192d53f83ee8f69da6
Cleaned up includes a little

Older compilers need the vector include in the header, made slater and
gaussian tools more consistent.

Change-Id: I7feae4cf754667ef83fddf580b10e93c79980809
Merge topic 'quantum-refactor' into master

34da294f Cleaned up includes a little
1522bb69 API changes to fit with Avogadro style
45e04913 Refactor the classes for quantum mechanics