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/ec_prv.pk8param.pem

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGTAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBHkwdwIBAQQgx+/F1F/nMZkz0NYVZGG7t1bwXPXP
+NhMhimhr5AKNT5OgCgYIKoZIzj0DAQehRANCAARkJXH1LofHesYJwJkoZQ0ijCVrxDFEi8e/fc1d
+6DS2Hsk55TWpL953QEIDN8RmW01lejceK3jQWs0uGDenGCcM
+-----END PRIVATE KEY-----