ISOProperties no longer needs its hack to refresh the game list, the
new INI Modified event can be used instead.

[UI] Remove browse toolbar button and tweak empty gamelist message

Removed some related functions

DriveReader::m_size was never initialized which was indirectly
causing CGameListCtrl to crash Dolphin when it tried to insert a
character at a negative index in a string.

Reading one sector at a time is very inefficient and appears to
be causing timing issues during boot so SectorReader has been
enhanced to support batching.

SectorReader has been given a working cache system.

This was done because showing a column was broken:
Showing a column repopulates the column with no regard for the sorted
order. This results in a seemingly random order.
(actually the order of m_ISO_FILES)

Just some extra cleanup.

When compressing multiple Wii games, the warning used to be showed
once for each game. Now it only appears once at the beginning.