RowFormWidget: add SaveValue(uint8_t) overload

Prepare for optimised enum code path.
RowFormWidget: use templates to work around alignment compiler warning

Switching the Android build to gcc 4.7 (NDK r8d) gave us new compiler
warnings about cast alignment.  This patch fixes this once and for
all, and adds a new optimised code patch for enums based on uint8_t.
AirspaceSorter: Fixed SortByName() method

SortByName was only sorting the first 4 characters by design, which is
useless. We now sort by the full name instead which gives us a proper
sorting.

This fixes ticket #2528
Screen/Fonts: fix log_infobox_units initialisation

This fixes a data loss bug introduced by 4ee52479.  It was a
copy'n'paste error that initialisation log_infobox_small instead of
log_infobox_units.
Screen/Fonts: make units non-bold

Non-bold units are just fine, the unit does not need to be so
prominent.  They never were, because of the bug in 4ee52479, fixed by
901da656.
Manual data_files: Typo.