Adds git hash to compiler's version switch. Refs #1119.
Add support for structs/unions defined in structs/unions
Added test for anonymous structs and unions
Removed time and added a hash based on filename, line and column for creating a unique struct id
Sorting enumerations and generation of consts for enumfields with the same value + test
Made the code more robust and detect nkPrefix as number (-1 or +4) for enum sorting. Added also a new test for enums.
Forces babel package descriptions to end with a dot.
Hyperlinks together importc like pragmas.
Starts backends.txt with bits from nimrodc.txt.
Hyperlinks back JavaScript target.
Starts nimrod calling backend section.
Adds nimrod to backend examples.
Adds examples of backend calling nimrod.
Mentions memory management.
Adds tidbit about threads.
Add keepIf proc and keepIfIt template to sequtils
Fix generation of package-dependent init names.

The code incorrectly used relative instead of absolute paths to
see if *.babel files could be found, which could result in them
not being located properly.

Also added an underscore between the package and the module name
for package_moduleInit() and package_moduleDatInit() so that there
won't be spurious conflicts, e.g. for package A and module BC vs.
package AB and module C.
Rewords C derivate backend. Refs #1299.
Mentions nodejs in js intro. Refs #1299.
Add missing operators for uint and uint64: `+=`, `-=`, `*=`