Introduced lcd_strlen() and lcd_strlen_P().
Replaced the old functions where necessary.
Reworked language_ru.h.
Speeded up test for zero length string in cardreader.cpp
First cleanup. Moved all code to cpp files, so there are no dependencies on pde files. And no more odd requirement to cat files together. (Still need to fix the Makefile). Also cleaned up some defines and made defines upper case as by C coding conventions.