make sure appraisal gemfiles use the same appraisal version as main gemfile
it should be jtds Closes #283
Merge pull request #281 from gregors/update_appraisal_in_gemfiles

make sure appraisal gemfiles use the same appraisal versions.
Merge pull request #284 from kares/master

fix the (for some adapter gems) broken **1.2.4** release
version bump
markdown-ize and review README