Support read/write on socket file descriptors.

Add test_websockets_bi_fileops to test using read and write instead
of recv and send respectively. Uses same source files with
USE_FILE_OPS define.
Shared file-descriptor nums for files and sockets.

Also, add FS.createFileHandle(stream) and FS.removeFileHandle
functions for adding to and removing from the streams/file-descriptor
table.
* Added symlink support.
Added a symlink testcase.
fixes strcat so that it returns the correct value

It should return the "dest" pointer that was passed in.
test_strings has been updated with a test for the correct behavior.
Add a select_const for selecting the const method implementation if there are only two.

Conflicts:
	tests/embind/embind_test.cpp
snip dead code
namespace the binding struct a bit more
Snip some dead code
checkpoint object handle composition
Add isAliasOf for seeing if two embind handles point to the same underlying object.

Conflicts:
	tests/embind/embind_test.cpp
Add a benchmark for calling from C++ into JS via interfaces
Add a test for interface methods that return void.
Oops, fix a test leak.
* Added some colors to messages displayed from python files.
Displays usage when no argument is passed.
tweak some logging levels
fix some logging uses
restore warning on no input files, to match gcc
update tests