Added proper licensing info #SSI_Alterations

Added COPYING and COPYING.LESSER file, as required for LGPL license
Added header to all files with copyright info and license info
Added CONTRIBUTORS file and updated .gitignore #SSI_Alterations
Updated documentation significantly. #SSI_Alterations

Added Roadmap
Added information on project to documentation index page
Added statement of license (LGPL) and copyright
Added support page
Added publications page and request to cite me
Added page on intended audience
Added links to Support and Publications pages to TOC #SSI_Alterations
Renamed README to README.rst to get proper markup used on Github #SSI_Alterations

Also changed setup.py to read this new README.rst file
Removed debugging print statements.
Updated .gitignore to ignore iPyNotebooks.
Finished all updates for Spectra. Now v1.2

Main change was for HeteroLambertian, to allow Spectra to be used for
either or both of the reflectances given.

Also updated docs for this, and bumped version to 1.2.
Updated release notes and roadmap.
Updated release notes and roadmap.
BUGFIX: Fixed errors when running BRDF GroundReflectance
Merge branch 'master' of github.com:robintw/Py6S
Bumped version to 1.2.1
Updated setup.py to work better

1. Put README file inline, as some users got errors saying that it couldn't find the README.rst file.

2. Removed dependencies on matplotlib and numpy, as it seems to try and install these even if they are already installed.
Updated Roadmap to add dates for all versions.
Updated version number in docs.
Fixed bug with importing Pysolar wrongly.

Two issues:
1. Was using import solar not import Pysolar - no idea why it stopped working. It used to work but has broken now.

2. The exception wasn't working when it wasn't installed - fixed by replacing to ImportError
Updated release notes.
Fixed issue reported by Daoxi Zhang with importing from AERONET data.

Issue was due to not all Cimel instruments used in AERONET having a
filter at 500nm. So, the code now does the right thing and tries to find
the closest AOT measurement to 550nm - giving a warning if further than
70nm away from 550nm.
Bumped version to 1.2.4, updated release notes.