MakeGccArmEclipse exporter

New exporter additon - eclipse, a project based on Makefile ( for eclipse with GNU ARM plugin).

As you have noticed, some tools reuse other tools, so a distinction needs to be implemented. I came up with a tool and a toolchain. Tool is IDE or makefile or whatever uses a toolchain. So we have make_gcc_arm as a tool, as a name says it's gcc_arm toolchain with Makefile.

The dic for current tool/toolchains:
<pre>
+    TOOLCHAINS = {
+        'iar' : 'iar',
+        'uvision' : 'uvision',
+        'coide' : 'gcc_arm',
+        'make_gcc_arm' : 'gcc_arm',
+        'eclipse_make_gcc_arm' : 'gcc_arm',
+    }
</pre>

This should complete #30