Use inline random number functions internally, fix unknown symbol

Move inline random number functions into random.h for internal use
by modules within the library other than random.c. This increases
code size but should allow more compiler optimization and is
probably faster.

Fix a typo in a function name in random.c that resulted in an
unknown symbol being exported in the library.

Bump version to v0.2.1.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>