Fully-tested merge to a single repository with development focus

Please see: http://adamcandy.github.io/QGIS-Meshing

MERGE: I have sorted the merge, as I'd originally planned, in preparation for Jose and Magda's return. The engine tests current development, including mesh_surface (and passes).

BUILDBOT: I have tied the now functional test engine to a buildbot, with commit hooks, so that the trunk and all development branches are continuously tested. (Note these are passing for the master and main dev branch).

DEV/RELEASE: Stripped out the near-duplicate 'release' version to avoid confusion, and cleared up project so it is much easier to navigate. Key directories are all now in the root.

WEBPAGE & GUIDES: I have created a web page for the project with guides on installing, developing and testing the plugins - with a link to the manual.

ISSUES & MILESTONES: I've created a list of issues tied to planned milestones - please edit, add and
complete. These are up on the linked-to repository pages.

As Gerard highlighted, there are several places where development is taking place - these now either have a note stating where the up-to-date development is taking place, or have been removed. Notes on how to develop and how branches are tested and merged in are up on the webpage. The project is now hosted in one place and is all together in a single repository.