Merge pull request #1886 from joshmoore/simplejson_upgrade

Use python's json rather than Django's
Merge pull request #1887 from bpindelski/11797-exceptionwindow

Fix import exception window layout (see #11797).
Merge pull request #1889 from jburel/download-crash

Download crash
Merge pull request #1891 from jburel/search-crash

Group was excluded.
Merge pull request #1892 from jburel/download-screen

Plate download
Merge pull request #1893 from jburel/viewed-by-crash

Check that the correct component is visible.
Merge pull request #1896 from jburel/tag-selection

Tag selection
If invalid interval set it to range wrt pixels type
Do not allow admin to remove himself/herself from system.
merge develop -D org -I include -E exclude: PR 1838 (Connection)
merge develop -D org -I include -E exclude: PR 1888 (Update develop submodules)
merge develop -D org -I include -E exclude: PR 1890 (Fix units if value is 0.0)
merge develop -D org -I include -E exclude: PR 1894 (Add DBUserCheck to create a Roles object from the DB (See #11813))
merge develop -D org -I include -E exclude: PR 1895 (Exclude some DEBUG logging from Blitz.log)
merge develop -D org -I include -E exclude: PR 1897 (Layout issue)
merge develop -D org -I include -E exclude: PR 1898 (Admin fix)
merge develop -D org -I include -E exclude: PR 1899 (Reset Image.archived flag where necessary (Fix #11810))
merge develop -D org -I include -E exclude: PR 1900 (Ajax content type 11821)
merge develop -D org -I include -E exclude: PR 1901 (img.getProject() no Errors if multiple parents. See #11807)
merge develop -D org -I include -E exclude: PR 1902 (Set global min/max according to pixel type. (see #11840))