cache last install tab active in localStorage
cache last install tab active in localStorage

Test Plan:
Change tab, click to other plugins, same tab is active. Close browser
tab, revisit, same install tab shown by default. Did not test closing browser.

Reviewers: spicyj, xymostech

Reviewed By: spicyj

Differential Revision: http://phabricator.benalpert.com/D63

shaialon/vim-awesome,vim-awesome/vim-awesome,vim-awesome/vim-awesome,jonafato/vim-awesome,divad12/vim-awesome,jonafato/vim-awesome,shaialon/vim-awesome,vim-awesome/vim-awesome,shaialon/vim-awesome,starcraftman/vim-awesome,divad12/vim-awesome,shaialon/vim-awesome,jonafato/vim-awesome,divad12/vim-awesome,starcraftman/vim-awesome,starcraftman/vim-awesome,jonafato/vim-awesome,starcraftman/vim-awesome,vim-awesome/vim-awesome,vim-awesome/vim-awesome,divad12/vim-awesome