create vendor folder & add freeRTOS 7.3 from lpcopen

vendor/freertos/README.txt

@@ -0,0 +1,21 @@
+
+This includes un-modified version 7.3.0 of the core FreeRTOS files, with the
+demos removed from the source tree to save space.
+
+The original files can be downloaded at:
+http://www.freertos.org
+
+Information on FreeRTOS licensing is located in the freertos/license.txt file
+or go to the website.
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+The following files have been modified to add support for a custom tick. This is
+needed for the dual-core M0 FreeRTOS tick function (no sysTick on the LPC4350 M0
+core).
+software\freertos\freertos\Source\portable\GCC\ARM_CM0\port.c
+software\freertos\freertos\Source\portable\IAR\ARM_CM0\port.c
+software\freertos\freertos\Source\portable\RVDS\ARM_CM0\port_m0.c
+software\freertos\freertos\Source\portable\RVDS\ARM_CM0\portmacro.h