Revert "Be less conservative about reprinting Statement nodes."

This reverts commit 0ebb6e41315fcbb45571f2aeb6ae7571ac7d676a.

The reasoning behind this commit was not completely correct, as
demonstrated by example/add-braces:

    if (test)
        f();

would become

    if (test)
        {
            f();
        }

instead of

    if (test) {
        f();
    }

because I was optimistically reprinting the BlockStatement into
exactly the same location as the original ExpressionStatement.
Depend on standard NPM Esprima instead of my own fork.

The current version is 1.0.3, and all of the Recast tests pass with it installed.

Closes #29.
Bump NPM version to 0.4.4 in preparation for publishing.