read from the .asterisk_history file (and subsequently being duplicated
when written).  We weren't checking the result of fgets() which meant
that we read the same line twice before feof() actually returned non-
zero.

Also, stop writing out an extra blank line between each item in the
history file, fix a minor off-by-one error, and use symbolic constants
rather than a hardcoded integer.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@146359 65c4cc65-6c06-0410-ace0-fbb531ad65f3