New Theorems Module. Contributed by Udicoudco <udifoglle@gmail.com> on the mailing...

New Theorems Module. Contributed by 	Udicoudco <udifoglle@gmail.com> on the mailing list. Rebased on top of master.

	I've modified all the non-AMS theorem modules so they would be independent of packages. currently
	the code support \theoremstyle, but only with definition, plain and remark.

	I'v added a new theorem module that support the thmtools \listoftheorems.

	I've modified the syntax of all theorem modules, such that it would be easier to
	create a new one, or maintaining the ones that exists. Instead of using \newtheorem
	in the preamble of a lyaout, I wrote \lyx@newtheorem, and in each module I've defiened
	\lyx@newtheorem as fitted. This way, there is only need in the files thorems-base, and theorems-extended,
	instead of an .inc file for each module.

	I've added theorems-labels.inc, a file that suppose to be included in a "Numbered by type" module,
	to change the Label and the LabelCounter of the layouts in theorems-base.inc.

	Note that in this configuration, all non-AMS modules will clash with the AMS ones, and so as the
	proof versions. theorems-proof-std.inc suppose to be in the non-AMS while theorems-proof.inc
	should be included only in AMS variants.