Template: English tweaks
Template: replace hardcoded shortcuts with insets

This way if the shortcut changes or a user is using
a different bind file, the correct shortcut will appear.
Template: move ERTs to layout and remove two notes

The layout now takes care of \begin{article} and \end{article}
by using \AtBeginDocument and \AtEndDocument.

This makes the template a little more clean. The user no longer
needs to read the two notes explaining why the ERT boxes were
necessary. The user also doesn't need to think about why this
LaTeX environment exists.
Template: change 'Abstract' from a Flex to a Style

This looks more consistent with other templates to me.
Template: change 'Address' Flex inset into a Style

This looks better and gives natural separation between multiple authors.
Template: set ForcePlain to 'true' for email inset

This prevents the user from some mistakes, such as
embedding an itemize or ennumerate environment.
Template: use 'classic' decoration for email inset

This makes it clear that

  (1) the emails are in their own insets
  (2) the \email command is embedded in the \address command
Template: now also works with latex

Before, only PDFs were being generated so latex did not compile.

This is not efficient but could save the user some pain, which is
the goal of templates.

An alternative would be to set the default output to use pdflatex.