Servers should respect ENV setting when looking for config file

The simple server implementation provided with axis2c (http and tcp) assume that the axis2.xml configuration file is located on directory level up from the server binary. This is not correct if the server binaries are located on the system in a FHS compliant fashion.

The implementation should respect the AXIS2C_HOME setting as it is used for dynamically loading libraries it is better to assume that the configuration file will also be found in this location.