Code for DAC module STM32Fxxx series
Add prototypes to dac.h and small change to simplify alignment enum
Minor changes to doxygen content, no changes to code.
NVIC_Set_Interrupt_Priority: change to use 4-bit fields.
(viz STM32F10xxx Cortex-M3 programming manual PM0056 and
Cortex-M3-Generic-User-Guide.pdf)

Doxygen commentary added
Fix compile error
STM32F timers. Doxygen markup added, and some code changes:

1. Remove the extra mask (TIM_DIER(timer_peripheral) & flag)
in timer_get_flag. Not all flags in SR relate to IRQs and the flags that
do might be useful even if interrupts not enabled.

2. In a number of functions (e.g. timer_set_output_idle_state) that only
apply to advanced timers, add test for TIM1 and TIM8, as done in some others.

3. Added timer_force_event to manipulate the EG register

TBD DMA burst - can't get my head around why this would be useful.
Someone must have thought so!
Merging pull request #19 "STM32F timers. Doxygen markup added, and some code changes" by Ken Sarkies.

Merge remote-tracking branch 'ksarkies/timer'
Changed local build target for library and linker files.

- The library files are now being built into the lib subdirectory of the
  source.
- The linker files for each library are being copied into the lib source
  subdirectory.

Motivation: The relative locations of files in the source directory after make
are now the same as after make install now. This makes it easier to
reuse examples with their makefiles outside of the libopencm3
sourcecode directory.
Examples detect if they are being built in src dir.

If an example is in the libopencm3 source directory it will use the
locally built library instead of the system library.

When you copy an example out of the libopencm3 tree it will
automatically detect it and build using the system wide installation.
Merge branch 'master' into nvic
Revert nvic_set_priority to original form. Minor doxygen markup changes.
Use make wildcard command for source dir detect. Library path fix.

Thanks ni!
Update to doxygen comments to fix promiscuity problem (see later)
Tiny doxygen mod to get all constants to show in doc output
And a bit more doc mods
STM32F1xx: Changed markup to get more control over documentation, each
file having its own group module rather than using @file.

No code changes except for the following:

gpio: Added function to map the eventout signal plus two Remap functions
dma: Prevent changing base addresses while channel enabled (see datasheet)
pwr: Added pwr.c (new file)
timer: Removed the last function that I introduced recently; there is already
an equivalent function present. Changed some parameter names for consistency.
Merging #18 pull request. Adding nvic documentation.

Merge remote-tracking branch 'ksarkies/nvic'
Merging pull request #23 Changed markup to get more control over documentation.

Merge remote-tracking branch 'ksarkies/doc'
Minor build system fixes.
ADC documentation added
In adc.h additional defines needed to assist documentation - lines 172-191
added, and 384,436-451 are duplicates of earlier defines to complete
parameter sets (compiler has no trouble with these).

Minor doc corrections to other files.

No code changes (apart from additional defines).
STM32F1xx Additional minor changes to adc.h and adc.c