Use LLStringUtil::getenv() or getoptenv() whenever we fetch a string that will
be used as a pathname.
Use LLFile::tmpdir() instead of getenv("TEMP").
As an added extra-special bonus, finally clean up $TMP/llcontrol-test-zzzzzz
directories that have been accumulating every time we run a local build!
Change LLControlVariable::mPersist from bool to tri-state enum. Its 'true'
value used to mean "persist only if changed from default;" third state now
means "persist regardless of value." Add forcePersist() method to set that.
Replace isSaveValueDefault() method -- used only by logic to determine whether
to save the variable -- with shouldSave() method to encapsulate ALL that logic
rather than only part of it. shouldSave() recognizes PERSIST_ALWAYS state.
When loading an unrecognized control variable from a user settings file, use
forcePersist() to ensure that we later save that variable again.
Tweak one of the unit tests to adjust for new semantics.
Nat Goodspeed