[Cmake] MS Project dsp regeneration

[Amitha Perera]

> 2. You could use the Clean and ReBuild all options on MSDeve without being
> inundated with the "dsp file has changed on disk would you like to
> reload?" questions.

Couldn't you avoid this by actually writing the .dsp if and only if
the contents change? For example, the DSPWriter could write to a
temporary file, then compare the original with the new, and update the
original only if necessary. This would give flexibility, so that you
are prompted for reloading only when you've actually made a change
that warrants reloading.

Previously, a number of out users have run into "problems" because the
DSP did not reflect the CMakeLists.txt. Being able to edit the file
within VS, and having the change take effect immediately went a long
way toward solving those issues.

[ However, I don't develop under VS, so my opinion is probably not
worth much. :-) ]

Amitha.