This repository is used twice: for GWT and for PG toolchains, under
different names:
* codemirror_minified for GWT
* codemirror-minified for PG
In I1e75690fe1 the external repository names were harmonized, but
renaming of codemirror_minified to codemirror-minified was undone
to avoid collision between the two external repositories.
Make them unique and rename codemirror_minified to
codemirror-minified-gwt to avoid collision.
Change-Id: I14c2f319d0ca451dea9424af9f5080d89dc704ad
d2f001b0c4