h5edit

Stage 1 of --atomic option implemented.
Expected output testfiles because the help page
now consists of the --atomic option.

test/testh5edit.sh:
    Updated with couple syntax checking --atomic tests.
    Also, deal with the possible presence of the backup file.
    Tool now exits non-zero (1) when it encounter errors
    during command execution.

src/parse.y:
src/main.c:
src/h5edit.h:
src/private_definition.h:
src/parse.c:
src/misc.c:
    code to support --atomic options added.

Tested: jam and koala.