Code review request: Preserve cached description files (option -Z)

[GoogleCodeExporter]

By adding another no-argument option, and "forwarding" its setting
to the CacheDetails class, it's possible to preserve existing cache
details files.
This results in a major speedup of some kinds of searches (e.g.
-x myfindgpx -q user $MYSELF) where it's not necessary to stay 
up-to-date with cache descriptions.
It also provides a means to keep existing cache details over multiple
runs of geotoad, for regression tests, or for multiple output types
(as in the GSAK case).
I have started to test these changes but would appreciate comments
and suggestions.

Original issue reported on code.google.com by Steve8x8 on 11 Jan 2011 at 9:18

[GoogleCodeExporter]

Summary adjusted

Original comment by Steve8x8 on 14 Jan 2011 at 8:59

• Changed title: Code review request: Preserve cached description files (option -Z)

[GoogleCodeExporter]

Original comment by Steve8x8 on 1 Apr 2011 at 2:10

• Changed state: WontFix