fix(install): Make installer usable on smartphones
chore(install): Point docs links to learn.elgg.org instead of docs.elgg.org

Refs #6784
fix(ui): Corrected bad stretching of non-square, large avatars. Now upscaling by width.

Fixes #5602
docs(upgrading): Added upgrade instructions for 1.8 to 1.9

Closes #5900
fix(collections):  make urls work regardless of username

Fixes #6059 - adds a second parameter 'owner' to the url for pages listing collections owned by a user.
Previously the page could not be accessed if the username was 'add'
Merge pull request #6958 from beck24/collections_pagehandler

fix(collections):  make urls work regardless of username
Merge pull request #7000 from Srokap/ticket_5602

fix(ui): Corrected bad stretching of non-square, large avatars. Now upscaling by width.
Merge pull request #6984 from ewinslow/docs-upgrading

docs(upgrading): Added special upgrade instructions for 1.9
Merge pull request #6967 from ewinslow/install-mobile

fix(install): Mobile-friendly installer