tmgr library fix (now need testing)

[webconn]

Commit 0e4d8aa

[nekromant]

I quickly looked through your code, so here goes my small code rant^Wreview:
Style:
0. All commits should have tmgr: prefix on the first line. This makes easier to find what subsystem has been affected by your work.

1. Do NOT use // for comments, only /* comment */. We are at least trying to follow Linux kernel coding style, and they are prohibited.
2. Identation is not Linux kernel style.

RTFM: https://www.kernel.org/doc/Documentation/CodingStyle

You can also use checkstyle.pl from linux kernel dist (running this against the rest of the code is still a big TODO)
The rest:
3. Protect atomic parts of your code with ANTARES_DISABLE_IRQS/ANTARES_ENABLE_IRQS defined in arch/antares.h. This is the cross-mcu friendly way to do that, now supported by most architectures.
4. NULL is checked and defined if necessary in generic/macros.h, just use that header. No need to duplicate that.
5. Most architectures (gcc-based at least) can strip unneeded functions, so it's safe to ditch CONFIG_LIB_TMGR_EXTRA. SDCC can't do that, but they are not a very big overhead anyway compared to the whole library. Just implement ticks to seconds and vice versa conversions via preprocessor macros.
6. Remove any remaining TODOs
7. Add doc/ru/tmgr.txt and doc/en/tmgr.txt with some documentation and guidelines.

Once your fix that stuff I'll give it a try to compile against different architectures to see if it works fine and merge. Thanks.

[webconn]

Now timers looks more like in Linux kernel. Check it out and see docs. Now it needs testing!

[nekromant]

Looks a lot better. Unfortunately, I can't test it right now since I'm in Minsk till the end of the holidays.
I'll see to it once I'm back. Besides, as far as I remember this one requires also proper locking api #48, which is yet to be pushed to git.
P.S. There seems to be a merge conflict right now. See if you can rebase your branch against the current git master.