add the image size (in pixels) to the info module

adds a new variable "show_size", so had to increment the version number
to 3

Conflicts:
	modules/info/classes/Info/Hook/InfoInstaller.php
fix whitespace

Conflicts:
	modules/info/classes/Info/Hook/InfoInstaller.php
fix upgrade function

allow for sequential upgrades

Conflicts:
	modules/info/classes/Info/Hook/InfoInstaller.php
internationalize image size display

as per comment
https://github.com/gallery/gallery3/pull/394/files#r4643737
change "size" to "dimensions" and display unit "px"

Conflicts:
	modules/info/classes/Info/Hook/InfoInstaller.php
Fix up a couple of cases where we were using Gallery 3.0.x idioms