Add Arch build instructions
support ctrl-shift-home/end on Windows

fixes issue #2989
Arch requires export PYTHON=/usr/bin/python2 to build
Cleanup linux build instructions
Update linux.md

Improve installation instructions
Fix typo
Fix abbreviation
Merge pull request #3014 from Frozenfire92/patch-1

Improve Linux install instructions
Merge pull request #2992 from maschs/ms-buildArch

Add build instructions for Arch
Fix a bug where scopes were being duplicated for every single token

This improves scroll performance by generating many fewer span elements
to render lines.
Fix typo in event trigger

destoryed -> destroyed
Update Windows build instructions

Just a few suggested changes to reflect experiences over a few months of building on several Windows machines.
- The Posix tools comment doesn't seem to be applicable (anymore)? 
- Added further instructions when using pre-installed Git.
- Added the frequent issue of first-time build failures (random `node-gyp` errors), which don't reoccur on second try.
- Added a few extra words on opening a new issue, to clarify that appropriate details should be provided, if the issue hasn't been reported before.

Feel free to amend or suggest further changes.
corrected grammar
typo
Merge pull request #3021 from dmnd/patch-1

Fix typo in event trigger
Merge pull request #2994 from jordanbtucker/patch-1

support ctrl-shift-home/end on Windows
Upgrade to apm 0.81
Upgrade to language-yaml@0.12
Export ReactEditorView as EditorView from 'atom' module

Also, remove a few early requires of 'exports/atom.coffee' in the spec
suite that were causing failures.
Base editor dimensions on the wrapper view

The goal is to make the editor behave like a standard block-level
element.

The horizontal behavior is simple: we stretch horizontally to fill our
container.

The vertical behavior is more nuanced. If an explicit height is assigned
on the wrapper view, we honor that height. But if no explicit height is
assigned, the editor stretches vertically so that its contents are
visible.

This prepares us to support mini editors, which need to be 1-line tall
without an explicit height assignment.