Replace "idl_aux_files" with property in all project

[AML14]

There is some code which refers to the name "idl_aux_files". Instead, the "aux_files_folder" property placed in /src/main/resources/config.properties should be used.

[RobertoHermoso]

There is a problem with the config.properties file, when the project is exported to a JAR file, the code will read the files from the current project relative path, it will not read the jar internal files , so the code will not read this file unless we auto generate the file as the first config.properties file in idl_aux_files

[AML14]

There's only one config file now, which is accessible by the JAR file. Solved.