Fix regression on RVKCs that was introduced ca3c3a7b56d7c82441e1071a658f3e0537a97d48, along with some tests to ensure it doesn't happen again.

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2450 ed100bfc-0583-0410-97f2-c26b58777a21
Added a missing changelog entry for the fix to https://github.com/spacetelescope/PyFITS/issues/8, which needs to be backported to the release branches

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2454 ed100bfc-0583-0410-97f2-c26b58777a21
replace distribute_setup with ez_setup

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2455 ed100bfc-0583-0410-97f2-c26b58777a21
Move all tests specifically related to VLAs to their own class, grouping them together.  This will make it easier to find them in the future.  This feature, being rather complicated, really deserves more thorough testing to begin with...

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2456 ed100bfc-0583-0410-97f2-c26b58777a21
An initial solution to the basic problem showing up in issue #47.  The more I look into this though the more apparent it becomes how naive the code is for managing the heap, especially when updating existing files.  I'm going to write some more tests to illustrate some of the problems I think are likely to occur with the current code and see if I can cobble together some slightly more sophisticated heap handling.  This might also fix some other VLA-related issues.

git-svn-id: http://svn6.assembla.com/svn/pyfits/trunk@2457 ed100bfc-0583-0410-97f2-c26b58777a21