Measurement can now be taken on PIC32MX250F128B platform.

    * configure.ac: Added LDFLAGS definition to wrap main
    * src/common.mk.am: Added linkerscript
    * src/platformcode/pic32mx.ld: Linkerscript for the pic32mx
    * src/platformcode/pic32mx_startup.s: Added code to jump to the
        reset vector in the pic boot memory
    * src/platformcode/platformcode.c: Toggle PA4, as well as a wrapper
        around main, so that exit is called, instead of main being
        repeated.