Make it easier to put project IDE files in VCS that mix with personal settings.

[fuzzyweapon]

There are two problems that occur in the .idea folder:

• when using composite configuration, this can mix in extra settings into files such as compiler.xml for the extra modules, but there can be important information that needs to go into vcs.
• personal plugins also might mix in their per project configuration into core project configuration files (i.e. JB's Grazi plugin - a multilingual proofreader and grammar checker)

Solution to spike...
Use pre-commit hooks to allow for changes in the .idea directory that are not on the index (not yet added) to be shelved/stashed automatically so that developers do not need to worry about changes to tracked files in the .idea directory being accidentally committed.
to spike

• does this idea play well with the IDE?
• does a bash script work on both the standard git windows setups (ming64 and cmd) and macOS?

pros

• theoretically works for CLI and IDEs
• changes to project folders need to be explicit (in IDEA, it's very easy to mix ide project file changes in with regular commits)

cons

• git hooks aren't easy to distribute. We'd probably want to adopt a little git hook manager or use a gradle task from a plugin like we do for composite configuration to pull down and install the hooks on a repo. This doesn't cover updates to those scripts though, and that's something to consider.
• It's possible that both batch and bash files must be maintained?