Fix GCC warnings

Some were found with the addition of -Wshadow.

Mostly just casting (e.g. dropping volatile), but also some unused variables were commented out, and an out of bounds array access was fixed in Ui_SoftBar_Setup().

Pragmas were added to silence strict-aliasing warnings, and the affected macros were reformatted for better readability.

With the addition of these changes, no warnings are seen during the firmware build.