Fixed font glyphs always being 2 pixels larger than they are supposed to be in each dimension, fixed wrong underline offset with some fonts, offset underline and strike through by half of their thickness so their center is positioned correctly, changed glyph and font metrics to use floats instead of ints to support scaling better.
Source code changes.

* Changed newlines to \n.
* Removed whitespace before colons.
* Fixed several alignments.
Added support for 64-bit integers in sf::Packet