Starts improving release procedure

The goal of this branch is to make it easier to build the release
binaries, and if possible completely automate that so buildbot can do
it.
Adds dist/pypi.sh to build sdist and wheel
Merge branch 'v2.1' into 'buildbot-nightly'
Error checking for pypi.sh
patchelf can now be installed from Conda
Adds Conda build script
Error checking for conda.sh
Makes Conda run the full testsuite
Clears Conda cache
Uses an absolute URL
Makes sure TestMashupApp runs with the VTK package
Merge branch 'buildbot-nightly_/conda' into 'buildbot-nightly'
Automatically sets version number in setup.py
Fixes getting version
Fixes mktemp on OS X
Works around sed -i on OS X
Disables image comparison in Conda package

Anaconda has an 'examples' directory, which tricks runtestsuite.py into
thinking that the VisTrails examples are available. There are not, and
so shouldn't be tried.
Fixes path to generated package (make it absolute)
Removed dist/ubuntu scripts
CHANGELOG: *new
  Please keep up-to-date with changes since previous release.

README.md: Added prepare_release.py instructions

dist/prepare_release.py: *new
  Uses CHANGELOG to auto-generate version,hash,branch and copies
  release notes to mac and win binaries.

dist/mac/Input/README:
  Updated from changelog.
  Removed installation instructions.

dist/windows/Input/releaseNotes.txt:
  Updated from changelog.

scripts/create_release_wiki_table.py:
  Updated branch

vistrails/core/system/__init__.py:
 New globals VERSION and REVISION that makes it easier to auto-generate them