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/configs/README.txt

@@ -0,0 +1,24 @@
+This directory contains example configuration files.
+
+The examples are generally focused on a particular usage case (eg, support for
+a restricted number of ciphersuites) and aim at minimizing resource usage for
+this target. They can be used as a basis for custom configurations.
+
+These files are complete replacements for the default mbedtls_config.h. To use one of
+them, you can pick one of the following methods:
+
+1. Replace the default file include/mbedtls/mbedtls_config.h with the chosen one.
+
+2. Define MBEDTLS_CONFIG_FILE and adjust the include path accordingly.
+   For example, using make:
+
+    CFLAGS="-I$PWD/configs -DMBEDTLS_CONFIG_FILE='<foo.h>'" make
+
+   Or, using cmake:
+
+    find . -iname '*cmake*' -not -name CMakeLists.txt -exec rm -rf {} +
+    CFLAGS="-I$PWD/configs -DMBEDTLS_CONFIG_FILE='<foo.h>'" cmake .
+    make
+
+Note that the second method also works if you want to keep your custom
+configuration file outside the Mbed TLS tree.