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/dir4/cert91.crt

@@ -0,0 +1,11 @@
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+F37bizAMBggqhkjOPQQDAgUAA0kAMEYCIQDbrSV4ndH0vAR3HqJfBn8NT8zdvMjB
+qSJes6Qwa42b2wIhAKyoH0H+b1Svw8pMkvUYF4ElH5Cnn7gxb7Wl3arc0+hQ
+-----END CERTIFICATE-----