Since Kornel's commit at e2d41970, it is now possible to update the
tex2lyx tests with CMake. Note that this is a case where a make
target in the build directory can affect the source directory, which
might not be advisable.
Writing these policies down makes it easier for newcommers to
understand guidelines and the intuition behind them.
The two policies this commit adds were responses by Georg and Richard
to two threads on the mailing list. The policies are titled
"When to set a fixed milestone" and
"Can we add rc entries in stable branch?".
These should be used if any new style needs to be introduced in the stable
2.1 series: If the ForceLocal flag of the style is set, it will always be
written to the document header, so that even older 2.1 versions can read
and correctly output the document.
