API Defaulting composer core dependencies to to @stable

Required to ensure correct operation of
"composer create-project silverstripe/installer my-path 2.4.10"
(checkout with tags).
Removed @stable markers from 2.4 dev branch
FIX Include flushtoken when install redirects to successfullyinstalled
Merge pull request #47 from hafriedlander/fix/flush_24

FIX Include flushtoken when install redirects to successfullyinstalled
Merge remote-tracking branch 'origin/2.4' into 3.0
FIX: Put self.version in composer dependencies.

Now that https://github.com/composer/composer/pull/1883 is in Composer, self.version
will work as a requirement for framework & cms.  This will simplify the release
process a great deal.
Updated SS logo sample file
Merge remote-tracking branch 'origin/2.4' into 3.0

Conflicts:
	composer.json
Tagged 3.0.6-rc2
Tagged 3.0.6
Tagged 3.0.7-rc1
Merge tag '3.0.7-rc1' into 3.0
Merge remote-tracking branch 'origin/3.0' into 3.1
Show snippets in behat.yml defaults, more dev friendly

They should be hidden in CI, but its more of a cleanliness
activity, while snippets are a great time saver for devs
that they shouldn't need to go hunting for via CLI params.
Removed misleading comments and legacy requirement calls

The instructions in the init() function seem to be at odds with the current documentation which suggests that it is preferable to include requirements in PHP code rather than in templates.

Also the requirement calls here are supposedly included so that older themes still work - but how old are we talking? I would assume that these older themes would not be compatible with SS3.1, and the bundled Simple theme does not need these requirement calls in the init() function, making them redundant.

I am guessing that the Installer is primarily used by people just getting started with SilverStripe, so ideally this bundled example Page.php should provide a clear pathway to best practice SS development, rather than supporting out-dated code.
Addition of geographic files (gpx, kml)
Addition of geographical file formats (gpx,kml)
Merge pull request #55 from jonom/patch-1

Removed misleading comments and legacy requirement calls
Merge pull request #56 from gordonbanderson/3.1

Addition of gpx and kml files to 3.1
Correct YAML syntax