Removed extraneous space in **Viewing errors in logfiles**

Reading for content; editing for consistency.

Reading for content; editing for consistency.

Reading for content; editing for consistency.

Edit to paragraph format rather than short lines.

 1. The prefix is useful to know.
 2. The full list contains distractions and makes the page feel less authoritative.
 3. New/future projects aren't likely to go into JIRA.

The `HR` project in issues.civicrm.org was used for CiviHR 1.0-1.4.  When
the project was transferred to Compucorp, they moved issue-tracking to a
private system.  The JIRA `HR` project only exists for historical purposes.

https://wiki.civicrm.org/confluence/display/CRM/Pull-Request+Process

https://github.com/civicrm/civicrm-core/blob/master/.github/CONTRIBUTING.md

https://wiki.civicrm.org/confluence/display/CRMDOC/Git+Commit+Messages+for+CiviCRM

This isn't exactly an import. More of a re-write.

https://wiki.civicrm.org/confluence/display/CRMDOC/Contributing+to+CiviCRM+using+GitHub

Make the warning about running Ubuntu installation as root slightly more dire.

and reminding everyone to always use buildkit

ref:
https://github.com/civicrm/civicrm-dev-docs/pull/217#issuecomment-314945998

ref:
https://github.com/civicrm/civicrm-dev-docs/pull/217#discussion_r127111272

Add links for phpstorm xdebug configuration

- General formatting improvements.
- Change  "Ubuntu 12.04 or 14.04" to "Ubuntu 12.04 or later" because the
  buildkit install script is clearly designed to work for later versions
  of Ubuntu.
- Relocate troubleshoot steps to after configuration steps (so the
  reader doesn't stop reading when they see "troubleshooting".
- Higlight post-installation steps.
- New instructions for manually ading webserver settings after running
  `amp config`.
- More troubleshooting help.

This was in the general "buildkit" page, and I think it fits better in
the specific "civibuild" page.

This is a direct copy-paste from one section of the guide to another,
without any edits. When someone is installing buildkit, these steps are
easy to miss if they're located in the civibuild file.

The doc mentions the page "Administer => System Settings => Cleanup Caches and Update Paths" as a way to clear caches. This is half-true: it does clear `templates_c` and the `civicrm_cache` table, but there are other things that it doesn't touch. (Compare `CRM_Admin_form_Setting_UpdateConfigBackend::postProcess` with the `CRM_Core_Invoke::rebuildMenuAndCaches`.)

IMHO, `UpdateConfigBackend::postProcess` should be patched to just do a general system flush (`civicrm_api3('System', 'flush', array())`) -- but (for now) the page is misleading and we shouldn't direct people there.