Update mysqltuner.pl

* information_schema.ENGINES doesn't exist before MySQL 5.1
* table cache var. depends on MySQL version
Merge pull request #58 from JoeHorn/master

Update mysqltuner.pl
Fixed reporting for temporary tables created on disk. Created_tmp_disk_tables is a subset of Created_tmp_tables
Merge pull request #60 from eljrax/master

Fixed reporting for temporary tables created on disk. Created_tmp_disk_t...
Adding check for autoincrement keys

Not familiar with Perl, please double check.
Added name to contributor list.
Merge pull request #61 from colepatrickturner/master

Adding check for autoincrement keys
Version 1.4.0
Merge pull request #1 from major/master

Update from original project