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/dir-maxpath/Readme.txt

@@ -0,0 +1,10 @@
+These certificates form a very long chain, used to test the
+MBEDTLS_X509_MAX_INT_CA limit.
+
+NN.key is the private key of certificate NN.crt.
+
+The root is 00.crt and N+1.crt is a child of N.crt.
+
+File cNN.pem contains the chain NN.crt to 00.crt.
+
+Those certificates were generated by tests/data_files/dir-maxpath/long.sh.