Local variable cleanup

First batch of formatting fixes, submitting these before things get massively out of sync again.

I've tried to apply the following rules throughout the code:

 * Local variables should be declared within the scope in which they are used.
 * Read-only variables should be declared `const`.
 * Local variables used in only a limit range of the scope should get their own scope.

I've also tried being a bit more explicit in variable and function naming.

See merge request !113