Exclude XDG_CACHE_DIR by default

[Michael Terry]

Users don't want cache files I assume. Possibly can whitelist some other obvious stuff like ~/.thumbnails.

This should probably not be exposed to user. He/she doesn't care.

[Pete Goodall (pgoodall)]

I would argue this should be expanded to any directory in my home directory that is called [cC]ache.

For instance, ~/.mozilla/firefox/${profile}/Cache

[Josh Triplett (joshtriplett)]

Pete Goodall (pgoodall) wrote on 2009-03-03:
> I would argue this should be expanded to any directory in my home directory that is called [cC]ache.
>
> For instance, ~/.mozilla/firefox/${profile}/Cache

Too dangerous:

~$ find src -name '[Cc]ache'
src/linux-2.6/include/config/arch/has/cache
src/linux-2.6/include/config/x86/internode/cache
src/linux-2.6/include/config/x86/l1/cache
src/linux-2.6/debian/hdrtmp/usr/src/linux-headers-3.3.0-rc4+/include/config/arch/has/cache
src/linux-2.6/debian/hdrtmp/usr/src/linux-headers-3.3.0-rc4+/include/config/x86/internode/cache
src/linux-2.6/debian/hdrtmp/usr/src/linux-headers-3.3.0-rc4+/include/config/x86/l1/cache
src/Pdf-Presenter-Console/src/classes/renderer/cache
src/Pdf-Presenter-Console/build/src/CMakeFiles/pdf_presenter_console_test_library.dir/classes/renderer/cache
src/Pdf-Presenter-Console/build/src/CMakeFiles/pdf_presenter_console.dir/classes/renderer/cache
src/Pdf-Presenter-Console/build/src/classes/renderer/cache

A standard already exists for excluding other cache directories: http://www.brynosaurus.com/cachedir/ . Other backup software includes support for that standard.