Option to change the order of new element

Adding the support of “stack_order” attribute for “add_another”
function. This will decide where to place the new item.
use proper names
add another position
Merge branch 'master' into add-another-stack-fix
Merge branch 'save-to-post-parent'
Merge branch 'master' into add-another-stack-fix
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' into add-another-stack-fix
get latest (svn up)
add test for markup
add test for position
add test for default & relative position test

Is there a better way to test the position of the button relative to
meta box ??
fix typo
Merge pull request #247 from jitendraharpalani58/add-another-stack-fix

Add another stack fix