if there is no Global or User Global PLT file create a project local one

This removes the requirement that the user have a plt file in thier
home directory. This change will set the makefile use that PLT file if
its there, but otherwise it will create one local to the project. It
does this transperantly to the user. It also removes the old number 2
option from the README.md. A PLT file is actually not optional, since
its required for the 'make' command to finish. This change should
provide enough information for that to be redundant anyway.
fix a bug in the rebar warning

Previously if rebar was not there the makefile would blow up (the
indentation in the conditional was the problem). This fixes that.
add the PHONY to the makefile for the non-file rules

Rules in make are all geared towards files. It does a lot of stuff to
check and see if files have been updated and need to be rebuilt. When
you have rules that are not files it can result in some wierd
behaviour (as make rebuilds things that should not be rebuilt). You
get around that by telling make what rules are not files with the
'PHONY' variable. You may or may not hit this problem, but having
'PHONY' is just good makefile engineering and avoids those problems
entirely.
version bump 0.0.2

There has been a lot of change since the last release. So this bumps
the version to keep to semver.
Make the types a bit cleaner with the addition of constraint_op()
support full semver style version strings

This supports full [semver](http://semver.org) style version strings and correct
Version bump 0.1.0 (due to api change)
Fix invalid constraint test to conform to new API

The semver addition means that additional data is returned from
version parsing.
Merge branch 'sf/eric-semver'