added doc for how to change the sparse backend
addressing comments from Jai
Merge pull request #86 from wasade/sparse_backend_doc

added doc for how to change the sparse backend
Updated version strings for 1.1.1 release.
Merge branch 'master' into 1.1.1_release_prep
Fixed sparse backend doc headings.
Merge pull request #87 from jrrideout/doc_fix

Fixed sparse backend doc headings.
Merge branch 'master' into 1.1.1_release_prep
Merge pull request #88 from jrrideout/1.1.1_release_prep

1.1.1 release prep
Updated version to 1.1.1-dev.
Merge pull request #89 from jrrideout/1.1.1_postrelease

Updated version to 1.1.1-dev.