BUG/API: remove infer_types from replace and fix compiled regex bug
closes #3907.

@jreback merge-able? i can remove `_is_sequence` in a later pr if u want but that is low priority...
 u know what let me add some tests for the things i added to `common.py`
 did Travis check this?
 it did but i just pushed another commit so rerunning :|
 (passed the first time)
 ok now it's ready
 ok just recall if I changed something really low level  sometimes things break
 oh. what did u change that is low-level?
 no was a while ago 
 ah len is there for `StringMethods`. putting it back...
 and i will write a test so that someone doesn't take it out in the future
 although a test still passes because of my addition of `__iter__` to `StringMethods` a while back. i'm just going to add the test and keep `len` out of `is_list_like`
 oh i also need 2 change the replace docs i think...
 nope nothing about `infer_types` in there
 ok build is passing.
 @jreback merge-able round 2?
 looks good
very minor point - can u put next to where (or even include) as part of your other replace changes in release notes - then they r all together
