Fix #16951: Remove hardcoded 'Due date was' string

Signed-off-by: Damien Regad <dregad@mantisbt.org>
More i18n-friendly string for overdue label

Using a parameter within the language string avoids hardcoding of text
elements' order, which is better for translators.

Fixes #16951
Remove hardcoded file size unit 'k'

Fixes #16970

Signed-off-by: Damien Regad <dregad@mantisbt.org>
New API functions to print maximum file size

- get_filesize_info() returns the file size in the desired unit
- print_max_filesize() prints the span tag with maximum file size in
  desired unit, including tooltip in bytes

Updated language strings, refactored code to use the new functions

Issue #16970
Fix #16976: bug_actiongroup_page.php leaks code
Fix #16986: file_download.php adds buffer trash to file contents
Fix #16989: The bug_get_bugnote_count() function in the bug API always returns 0
Code cleanup

- remove unneeded variables
- replace ternary operator with array_splice call
Merge pull request #140 from dregad/hardcoded-strings

Fix hardcoded strings
Merge pull request #33 from mantisbt/master

push origin