Added HiFive1 to BOARD_INSUFFICIENT_MEMORY list for examples and tests that are too big to fit

build: fixed missing syscall and cpuid failures

Added missing syscall stubs for nanostubs and fixed compile error with cpuid periph

build: fixed whitespace error

build: add hifive1 to more BOARD_INSUFFICIENT_MEMORY

doc: fixed doxygen warnings

Addressed Doxygen warnings in source file comments

doc: more doxygen fixes

doc: even more doxygen fixes

doc: more changes

build: fix pedantic and rdci_simple build failures

make: exclude lua