Fixes #6492.  Port the patches from mysql-5.5.30 for backup.
{{{
svn merge -c 55276 https://svn.tokutek.com/tokudb/mysql.com/mysql-5.5.30
svn merge -c 55284 https://svn.tokutek.com/tokudb/mysql.com/mysql-5.5.30
}}}

git-svn-id: file:///svn/mysql.com/mariadb-5.5.30@55292 c7de825b-a66e-492c-adef-691d508d4ae1
Fixes #6598.  Merge the tokubackup_version variable from mysql:
{{{
svn merge -c 55587 ../mysql-5.5.30
svn merge -c 55588 ../mysql-5.5.30
}}}

git-svn-id: file:///svn/mysql.com/mariadb-5.5.30@55594 c7de825b-a66e-492c-adef-691d508d4ae1
refs #6559 correct result file issues from backup effort

git-svn-id: file:///svn/mysql.com/mariadb-5.5.30@55370 c7de825b-a66e-492c-adef-691d508d4ae1
refs #6378 build changes to put the hot backup lib in the builds INSTALL_LIBDIR

git-svn-id: file:///svn/mysql.com/mariadb-5.5.30@55467 c7de825b-a66e-492c-adef-691d508d4ae1
move the linking of pthread so that it doesn't interfere with backup
#12 build explain-filename-t with hot backup lib