gen_leader -- add debugging information to sys:get_status/1 response
incarnation -- refactor
incarnation -- refactor

read_file_info is redundant
incarnation -- make safe

If the disk was full then the incarnation file may be empty and the old
version will fail.
Merge branch 'fix_incarnation'
typo
Merge branch 'fix_incarnation'
Merge pull request #1 from r3m0t/master

Fix error starting up after disk was full