Use semicolon as a directory delimiter on Windows
Windows path names have ':' inside as a drive letter separator. The
widespread convention on that platform is to use ';' as a list separator
in file paths, so let's follow suite.
It looks like this multi-value searchdir is only used in `ly_ctx_new()`,
and that all other functions operate on one directory at a time.
diff --git a/src/context.h b/src/context.h
index 1859236..fdd87e2 100644
--- a/src/context.h
+++ b/src/context.h
@@ -214,8 +214,9 @@
* also affects the number of instances of both tree types. While you can have only one instance of
* specific schema connected with a single context, number of data tree instances is not connected.
*
- * @param[in] search_dir Directory where libyang will search for the imported or included modules
- * and submodules. If no such directory is available, NULL is accepted.
+ * @param[in] search_dir Directory (or directories) where libyang will search for the imported or included modules
+ * and submodules. If no such directory is available, NULL is accepted. Several directories can be specified,
+ * delimited by colon ":" (on Windows, use semicolon ";" instead).
* @param[in] options Context options, see @ref contextoptions.
* @param[out] new_ctx Pointer to the created libyang context if LY_SUCCESS returned.
* @return LY_ERR return value.