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/server3.key

@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MF8CAQEEGItTogpE7AOnjvYuTqm+9OabmsX02XKIAqAKBggqhkjOPQMBAaE0AzIA
+BH0AoQyUhPABS38y67uEVs4O3RXmKKrBdUR7/L2QPB8EC2p5fQcsej6EFasvlTdJ
+/w==
+-----END EC PRIVATE KEY-----