Support for PC platform (#12)

* improvements for cross-platform compiling

* moved tactility-core to libs/

* splitup improvements

* remove git/gitmodules from freertos

* better platformbetter platform checks

* added build scripts

* delete mbedtls

* re-add mbedtls

* fixes and improvements

* added pc build

* simplify build scripts

* revert build scrpit

* updated builds

* fix for pc

* fix for pc

* fix for build

libs/freertos-kernel/portable/readme.txt

@@ -0,0 +1,20 @@
+Each real time kernel port consists of three files that contain the core kernel
+components and are common to every port, and one or more files that are
+specific to a particular microcontroller and/or compiler.
+
+
++ The FreeRTOS/Source/Portable/MemMang directory contains the five sample
+memory allocators as described on the https://www.FreeRTOS.org WEB site.
+
++ The other directories each contain files specific to a particular
+microcontroller or compiler, where the directory name denotes the compiler
+specific files the directory contains.
+
+
+
+For example, if you are interested in the [compiler] port for the [architecture]
+microcontroller, then the port specific files are contained in
+FreeRTOS/Source/Portable/[compiler]/[architecture] directory.  If this is the
+only port you are interested in then all the other directories can be
+ignored.
+