Merge upstream version 0.5.0.
Some small updates from Jef Driesen since the last sync, but let's sync
with the real 0.5.0 release.
* tag 'v0.5.0' of git://git.libdivecomputer.org/libdivecomputer:
Release version 0.5.0.
Include the public header in the implementation file.
Add explicit casts for the msvc C++ compiler.
Add some workarounds for the msvc compiler.
Update the msvc project file.
Add missing header files to the Makefiles.
Add support for the Subgear XP-Air
534dd2f34b