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/cert81.crt

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----
+MIIBpTCCAUmgAwIBAgIBUTAMBggqhkjOPQQDAgUAMDExDzANBgNVBAMTBlJvb3Qg
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+YmVkIFRMUzELMAkGA1UEBhMCVUswWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAAT1
+GuTQ9vgf2l3oLM25r78cvIAQqE02GzQGjp/WWw3CysEwTwNEuZGhRiD5lDmkbUGW
+UNxv/7uJjy7k3K3fDNdko1AwTjAMBgNVHRMEBTADAQH/MB0GA1UdDgQWBBTHFA2h
+Au0tPnzeYnLcmlTQj4FAajAfBgNVHSMEGDAWgBTHFA2hAu0tPnzeYnLcmlTQj4FA
+ajAMBggqhkjOPQQDAgUAA0gAMEUCIH7Z/HNb/Pwbs40iNll1a9gmgAbYOgdlVPWo
+nSdcb7cZAiEAlhVb6CdBXsjOfAWWEET/QP74z608PKFccCIFPCDLkxo=
+-----END CERTIFICATE-----