Fix handling of ct results

* Return error on failed and/or auto skipped tests
* Print all results for quiet repeated tests
* Sum results of repeated tests

Change PLT name and directory

switch from loading modules to read compile info to using `beam_lib`

Add debug statements to dialyzer provider

New template defaults

Previously dialyzer stored the project PLT in ./build/, which meant the
same PLT was used for all profiles. This could mean partial rebuilding
of a PLT when switching between profiles.

fixes #216 and #220

fix for profiles_remain_applied_with_config_present fixes #212

Don't include directories when testing subset of ct suites

preserve state when compiling directories with a `rebar.config`

ct fixes

rebar state from propogating appropriately

shorter build dirs

move `_logs` and `_cover` to `_build` dir

to `as` used to generate them

Do not automatically check plt

Fix hg diffing

- fetch more complete refs for tags (may download more history than
  required, but it works)
- Fix comparison of tag distance by using lists everywhere

use rebar_utils:sh for git and hg commands to have better errors and log

use rebar_file_utils:mv instead of copy for fetched source

`cover` task

`as` delegates task handling to `do` provider

pre-purging before checking to facilitate long do chains

source files in the `compile` key of `module_info/1` so `rebar cover`
struggles locating source in some instances. in these cases a warning
is printed and crappy coverage info is written rather than none at all

`rebar.config` or via the `-c\--cover` flag given to the appropriate
task) from the `eunit` and `ct` tasks and add a `cover` task to
write coverage analysis to disk