Merge pull request #1 from sdestercke/master

deleted tab from arff
Add two small correction to arff

Explanation :
1. "esc" is not a built-in function, should use "self.esc"
2. some data have their attributes are apostrophed, some other not. A
normalization in the chode may be wise.
Merge pull request #2 from genyang/master

Add two small correction to arff