Define the EditWithExternalTool method and add it to the makefile to get it
built as well. Basic working model of external edit application.
This should work fine in all platforms given that I am using SystemShellExecute
ReRead method does an automatic refresh of the Shell

By adding the external method to the specific FN_EXTERNAL_EDIT identifier

Has the method that is invoked when edit with external tool is called

Needed the lcl_getPreferredExtension elsewhere, so moved it to hxx.

1) add unique identifier to cmdid.h
2) add ExecMethod and StateMethod to _grfsh.sdi
3) add additional details for the identifier in swriter.sdi
4) add the item to the popup menu in mn.src

When moving the right end of a table, the table alignment came to
Manual but this caused size weirdness when switching from web to print
layout. Using the "From left" option for the alignment keeps the size.