Adding a CONTRIBUTING document

Adding a CONTRIBUTING document to take advantages of this:
https://github.com/blog/1184-contributing-guidelines
add comps files for fedora19

copy fedora18 to fedora19 and remove those packages which made it to main Fedora 19
Issue 1712 - Incorrect error notification when creating user

No need to validate rolename when role  == self_role
Travis - Moving code linting to the same job.

The Ruby linter was previously a part of the minitest job but now
that we have JS linting, makes sense to put all linting together
and keep that separate from unit tests.
967103 - RAM and Cores limit displayed wrong

katello displayed RAM in megabytes in some places and gigabytes in some
other places. Making it consistent throughout the application.
969229 - require minitest for installation to support rails console

due to rails issue 6907 running rails console in production
requires minitest to be installed.  Since this is a highly
valuable debugging tool, we should allow rails console to be
run without additional packages to be installed
966256 - Fixes for new ldap_fluff API

Ldap configuration is now merged to katello.yml. /etc/ldap_fluff.yml
is not used anymore.
Merge pull request #2396 from ares/bug/966256_ldap_fluff_upgrade

966256 - Fixes for new ldap_fluff API
965724 - install foreman-proxy-installer as a part of katello-foreman-all
Merge pull request #2381 from xsuchy/pull-req-comps-f19

add comps files for fedora19
Merge pull request #2392 from komidore64/ram-in-GB

967103 - RAM and Cores limit displayed wrong
967467 - search for env by label when not found by name only for rhsm

Otherwise, katello-cli behaves strangely when addressing environment
by name, and it uses the label instead.
Merge pull request #2405 from jlsherrill/require_minitest

969229 - require minitest for installation to support rails console
969216 - retrieve org by label when org identified in pool details

When katello gets a pool from candlepin, the 'owner key' is
equivalent to the organization label.  This change is to
properly retrieve org by label vs name.
Technical Debt - Removing old JavaScript from previous Foreman integration.
915900 - Systems - Events History - Clear search does not work

Elastic search query was wrong and was not able to load system_event.js due to which the right results were not pulled.So we updated the type of task_owner_type in the search query which fixed the issue.
Merge pull request #2373 from mptap/rolename_validator

Issue 1712 - Incorrect error notification when creating user
Merge pull request #2333 from daviddavis/temp_1368975142

Adding a CONTRIBUTING document
Merge pull request #2407 from iNecas/bz/967467

967467 - search for env by label when not found by name only for rhsm
Merge pull request #2406 from iNecas/bz/965724

965724 - install foreman-proxy-installer as a part of katello-foreman-all