Remove access of undefined variable $t_bug_file_table

Regression introduced by commit 8178451
Copying or deleting an issue with attachment stored in database throws error.
Fix #8017: allow username up to 255 chars

Signed-off-by: Paul Richards <paul@mantisforge.org>
Allow realname up to 255 chars

Signed-off-by: Paul Richards <paul@mantisforge.org>
Allow password up to 64 chars

This enables future use of cryptographic hash algorithms such as bcrypt,
Whirlpool, sha512 or RipeMD.

Signed-off-by: Paul Richards <paul@mantisforge.org>
Allow email up to 255 chars

Maximum allowed length is actually 254. Reference:
http://stackoverflow.com/questions/386294/what-is-the-maximum-length-of-a-valid-email-address

Signed-off-by: Paul Richards <paul@mantisforge.org>
Remove unused variable/db_get_table call.

We only hit the bug table for the summary reports
Update db_get_table() calls for remaining tables

Commit ac49ad8 adds support for the new
table name syntax,allowing us to replace db_get_table calls within queries.

Calls to db_get_table that are used by other database function,
i.e. db_insert_id, db_field_exists are deliberately left unchanged at this
stage.

This is aimed at breaking down the future DB API changes into manageable
chunks, and to aid the review process after 1.3 for 2.0.