Option to disable timestamps

[swashbuck]

Subject of the issue

The timestamps that have been added in #3650 is causing some friction in our collaborative workflows in SVN. With every commit, timestamps are updated in the following files.

Problems

• When working as a team, this creates merge conflicts which must be dealt with. While it's not difficult to choose "accept incoming file", it still needs to be manually done.
• These files are added to most commits which clutters the change logs. In most cases, the only change is the timestamps.

Suggestions

1. Do not update timestamps when building with the grunt dev option. The grunt build option would still update the timestamps.
2. Add a new option to config.json called _disableTimestamps

[oliverfoster]

@hanshillen any thoughts?

[hanshillen]

That suggestion works for me

[swashbuck]

I probably prefer option #1 since it's simpler and doesn't require any new configuration properties. @hanshillen @oliverfoster Do you have a preference? I don't think we need to implement both options as it might be overkill.

1. Do not update timestamps when building with the grunt dev option. The grunt build option would still update the timestamps.

[oliverfoster]

Yup