Delete unused build files.

These files can still be built by running `make build`. However we remove them
from version control because they bloat the repo, especially diffs of minified
files, which are large.

.gitignore

@@ -41,3 +41,11 @@ develop-eggs
 
 # OSX
 .DS_Store
+
+# Builds
+converse-no-locales-no-otr.js
+converse-no-locales-no-otr.min.js
+converse-no-otr.js
+converse-no-otr.min.js
+converse.nojquery.js
+converse.nojquery.min.js