Fix some return values.
Merge pull request #142 from phazei/master-phazei

Fix bug where $this->columns is set to null instead of [] if selected.columns are empty for case of selecting all columns.
Update wildcard to add wildcard on wordbreaks, not between every characters

Fixes #144
Merge pull request #143 from phazei/fix-comments

Fix some return values.
Merge pull request #145 from phazei/patch-1

Update wildcard to add wildcard on wordbreaks, not between every characters
Fix the formatting of the keyword and consistency in it's use.

I realized that the formatting of the keyword with the wildcard_like_string doesn't put the % at the beginning and end of the string I don't think.

Also, I noticed when filtering a column with LIKE, it doesn't properly setup the keyword to match the other elements and the wildcard setting, so for the specific case of filtering with LIKE, it now does that.
Merge pull request #146 from phazei/patch-2

Fix the formatting of the keyword and consistency in it's use.
Don't modify keyword is already contains any wildcard

Just an addendum to #146