Bug 28576: Update the maximum size of an image.

Bug 28576: Update the maximum size of an image.

This patch modifies the maximum size of a patron's image, from 500KB to
2MB. Also, in Home/Patrons/anyPatron, when you try to add an image to a
patron, you can now see the supported file types AND the maximum size.

The following places are affected by this patch:
- Home/Patrons/anyPatron
- Home/Tools/Upload patron images
- Home/Tools/Patron card creator/Images

To test:
1)Search for any patron and go to his page.
2)Hover over the image area on the left and click on the "Add" button.
3)Notice that the message above the choose file button only specifies
file types without the maximum size.
4)Add an image bigger than 500KB.
5)Nothing happens. (This is because the maximum size is 5KB)
6)Apply the patch.
7)Repeat steps from 1 to 3.
8)Notice that the message now includes the maximum size.
9)Add an image bigger than 500KB, but smaller than 2MB.
10)The image is succesfully uploaded.
11)Add an image bigger than 2MB.
12)Nothing happens. (The maximum size is now 2MB)
13)Repeat the steps 9 to 12 in "Home/Tools/Upload patron images" and
"Home/Tools/Patron card creator/Images".
14)Notice that the maximum size is updated.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>