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/mbedtls/tests/data_files/server6.key

@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIEQZG5j8IkRLxa9OoZJzD3KkrXqIgi9cHZMVv2s/VcPOoAoGCCqGSM49
+AwEHoUQDQgAEgVkxdkkk+hWtq6Axbg7tMxH6kSVVwbDBnANyPpi6LaRyN4kfQzeN
+H4462PBX6C9PyQCk99tzD7LGBJTRQDs44w==
+-----END EC PRIVATE KEY-----