Document the extra_data argument to Backend.parse_answer

This has been there since forever, but didn't make it into the custom backends
guide for some reason.
Hiera 1.3: Document lookup functions in interpolation tokens

This commit also makes references to interpolation throughout the manual more
agnostic about what's being interpolated, as it may not necessarily be variables
anymore.
Remove "coming soon" space for a puppet backend example

It's not coming soon, sorry.
Hiera 1.3: you can now interpolate into hash keys
Hiera 1.3: Release notes (for RC2)
Note that datadir must be a string

See redmine #21669.
Merge branch 'hiera_13'
Console inaccessible on Ubuntu in PE 2.8.3

Added known issue and workaround for the console being inaccessible on
Ubuntu + PE 2.8.3.

This appears to affect upgrades, no only fresh installations

I initially didn't think a known issue was necessary, since most users
are not doing fresh installs of PE 2.8.3, but since it affects upgrades,
this probably needs to be publicly documented for customers.

https://jira.puppetlabs.com/browse/PE-1679
Added list of Puppet components to PE Overview page.
Fixed a couple typos in the PE Overview page.
Puppet 3.3.2 release notes
PuppetDB: New low catalog troubleshooting guide

This adds the new guide into the index for master, in ancticipation for a
future release.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #245 from zacharyalexstern/console_known_issue_ubuntu

Console inaccessible on Ubuntu in PE 2.8.3
Merge pull request #246 from kbarber/maint/master/puppetdb_trouble_low_catalog_dupe

PuppetDB: New low catalog troubleshooting guide
Tiny tweak to example in Learning
Added Known Issue re: stopping pe-postgres service. PE-1108
Use _ prefix instead of _real suffix on variables

On the whole, the style in manifests for variables that have been
modified in a local scope and saved to a new variable name have shifted
from using `$foo` -> `$foo_real` to using `$foo` -> `$_foo` due to the
shortness of the form and semantic implications that `$_*` is not
neccessarily human-friendly.