Qt/Logs: Fixing spaces, optimize string to html conversion

[elad335]

Every time that more than one space was repeated in a log message, the Qt log frame would display it as one. Replace it with non-breaking space. Also: Remove two redundant copies of the QString on HTML escaping when not needed. The first was being done by QString::toHtmlEscaped(), and the second was done as an unfortunate result of QString::replace() return lvalue reference, which creates a copy upon rvalue conversion. (this matters mostly for huge log messages)

Misc commits:

• Fixup SPU profiler floating point inaccuracies on bounds.
• Fix potential nullptr deference in savestates on saving. (race condition)
• Debugging improvements, add SPRX booting option and always log its function exports.

[Megamouse]

Please give people time to review your amalgamation of random changes in the future.