subversion: update to 1.7.11, add 1.8.1.

I have done some work on Subversion.  I started with the spec in the repo for version 1.7.6.  It didn't work correctly (a reference to {__rm} instead of %{__rm}).  I fixed that, and then updated it to version 1.7.11, adding some newer patches from Fedora, and removing some older things (references to local neon and Python that made the build fail).  So, 1.7.11 should be working and available for rh6.

I then added subversion-1.8.spec, which will currently build 1.8.1.  It is similar to the 1.7 spec, but with newer versions and patches.  I had to add a patch to force an Apache module to build (in upstream, and Fedora, that particular module has moved to a -tools package that we don't create).  I had to return to using a local build of sqlite-amalgation, because Subversion required a newer version.  I had to add a line to the configure command to force the http modules to be installed where expected.  This spec file can build 1.8.1 for rh6.

I haven't done any work on rh5.