add field parent_id in tasks

for sub-task feature
sub-task feature

updated current working version
this is all so far, but more to come
add field sibling_order in tasks

for later use
preset columns/fields for tasklist

include parent
made some small fixes around missing logo and version will be 1.0 instead of 1.0.0
Sub-Task / Super-Task

renamed for clarification and distinction:
- "parent" to "super"
- "child" to "sub"
added theme "CleanFS_wSubTs", restored theme "CleanFS" to default
rename "parent_task" to "supertask"
cleanup & fix

rename "parent" to "supertask"
rename "child" to subtask"
delete *.bak files
merging
Merge branch 'master' of github.com:Flyspray/flyspray
Switching from eval to stream wrapper
Upgraded adodb from v4.94 to v5.18 - tested locally with no issues. - Note: this is PHP 4.x breaking.
FS#1825 - Incorrect rendering projects->preferences
Fix for FS#1826 - Add new task - incorrect rendering
Partial Fix for FS#1803 - Exception when add new user.

class.notify was passing a null value to SwiftMailer which was overriding a default empty string.
Extension of Fix for FS#1826 - Add new task - incorrect rendering... as edit task had same issues.
Implementation of FS#1561 - Language selector

See comment on FS#1561 for rules.
Implementation of FS#1583 - "Due in Version": Default value needed
History tab now includes gravatars.
Assigned To is now including names with Gravatars.
Assigned To is seperated with a <hr> tag to make it look better.
Opened By includes a small gravatar.
Last Edited by includes a gravatar.
Due Date now includes Days Left, changes to red bold font when its 5 days left and under.
checks to see if there is a due date assigned so it wont show if its undecided.