Update blog/2013-01-31-safely-catching-a-list-by-its-tail.lhs

Lets -> Let's
Update blog/2013-01-31-safely-catching-a-list-by-its-tail.lhs

Removed redundancy + weird word "from"
Update blog/2013-01-31-safely-catching-a-list-by-its-tail.lhs

I feel like "to" is missing here.
Merge pull request #23 from Ptival/master

Some minor corrections