Repair to documentation (most documented files)

to remove errors, duplications and inconsistencies.
File lib/stm32/f1/pwr.c - all code removed as it duplicates that in common/pwr_common.c
Remaining changes do not affect code. Compiles OK.
TODO efm32 has no code so generates no modules
TODO F2 needs pwr.c
TODO L1 needs dma.h and dma.c

lib/stm32/common/crc_common_all.c

@@ -1,13 +1,9 @@
 /** @addtogroup crc_file
 
-@version 1.0.0
-
 @author @htmlonly &copy; @endhtmlonly 2012 Karl Palsson <karlp@remake.is>
 
-@date 15 October 2012
+*/
 
-LGPL License Terms @ref lgpl_license
- */
 /*
  * This file is part of the libopencm3 project.
  *