[Mojo] Remove static "bootstrap" state in mojo_js

This CL removes the static static in boostrap.cc that we used to transfer the
initial handle from C++ into JavaScript. Rather that storing the initial handle
in static state and evaling some script to kick off the loading process, we now
use an API to load a module by name and then pass the initial handle to the
function defined by that module.

This CL paves the say for adding threading support to mojo_js. The previous
static approach didn't scale to multiple threads, but the approach in this CL
does. I'll actually add the API to create a thread in the next CL.

R=aa@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/90203002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237647 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237647
fix +x on liblouis_list_tables.py

TBR=plundblad@chromium.org,chrisgao@chromium.org

Review URL: https://codereview.chromium.org/93193002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237648 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237648