Reduced the matrix size for float_matmult, to run on AVR

    * src/float_matmult/matmult.c: Execution fix for AVR
Added support for Cortex-M0

Assembly start up code now included in platform code. This is added to
the compilation list in the common makefile.

    * configure.ac: Conditionally compile startup code
    * generate.cortex-m3: Likewise
    * src/2dfir/Makefile.am: Likewise
    * src/blowfish/Makefile.am: Likewise
    * src/common.mk.am: Likewise
    * src/crc32/Makefile.am: Likewise
    * src/cubic/Makefile.am: Likewise
    * src/dijkstra/Makefile.am: Likewise
    * src/fdct/Makefile.am: Likewise
    * src/float_matmult/Makefile.am: Likewise
    * src/int_matmult/Makefile.am: Likewise
    * src/rijndael/Makefile.am: Likewise
    * src/sha/Makefile.am: Likewise

    * generate.cortex-m0: Created, generate for ARM Cortex-M0
    * src/platformcode/startup.S: Created, start up code for ARM
    * src/platformcode/stm32f05_flash.ld: Created, linker script for M0
Compilation fixes for M3: set entry point and correct define.

    * generate.cortex-m3: Small compilation fixes