moved startup timer to end of execution, as run timer
updated usage for linewrap
configurable line wrapping (80 default)

disabled when set to a value below 10
removed tag checkout when building
clarified upgrade process and note section
testing create/delete
make test is now single-threaded
travis using single-threaded testing
bumped version in Cargo.toml
extensive rewrite to use json for storage:

sqlite3 requires the directory where the database resides to be
writeable by the user. This presents a problem on multiuser UNIX systems
where they may want to limit areas where users have write access.

This rewrite totally scraps the sqlite3 database in favor of a pretty
simple json file consisting of an array of posts. flock(2) locking is
used to synchronize access to the file and make sure two clients aren't
trying to write to it at once. The locking is fairly granular right now,
but later I may change it to using a single lock for the duration of
execution since race conditions are *possible*, if unlikely for the
purposes of clinte's intended use.
expanded usage, removed extraneous info about crates
added test for tempfile creation
post ID can be specified as an argument. if absent, user will be prompted
prepopulating editor with post body when editing
editing a post calls $EDITOR