Merge branch 'release/2.3.2' into develop
Merge branch 'hotfix/2.3.3' into develop
Merge branch 'hotfix/2.3.4' into develop
Loosen dependency on sinatra-mustache version.
Remove unused rake package tasks.
Improve "remove server" button and confirmation.

Clarify that this removes settings but not data.
Add PHP and Ruby dependency versions to README.
Expose duplicate collection name error.
Add failing tests for #108

Adding malformed or empty server DSNs should return 400.
Return 400 when adding a malformed server DSN.

Fixes #108
Clean up any lingering empty string server DSNs

(PHP backend)

See #108
Mention fix for #108 in CHANGELOG.
Add `\db` back to the "add server" sample DSN.
Bump version for 2.3.5
Merge branch 'release/2.3.5'