Unhide sql-sanitize

As per https://github.com/drush-ops/drush/issues/89#issuecomment-24291299, unhiding sql-sanitize from help.
Adds note about how to assign issues.
Add a support section to the README
Add links to old drupal.org issues in README
Move usage section up.
Merge pull request #119 from greg-1-anderson/readme-support

Add a 'Support' section to the README file
Merge pull request #116 from patcon/patch-1

Adds note about how to assign issues.
Merge pull request #90 from jeff-h/patch-1

Unhide sql-sanitize
Fixing cygwin path conversion (See https://drupal.org/node/2036001)
Split table list returned by _drush_sql_get_db_table_list() correctly when on windows.
Exploding the newline-seperated string of table names only on newline characters (\n) leaves all corresponding carriage return (\r) chars behind. confusing all checks performed directly on the array, such as in_array. As e.g "sessions" != "sessions\r", $skip_tables oder $structure_tables will only contain the respective setting's last element.