Build image improvements

I am supporting a developer workflow where the project and docker source files are located on a Windows or OSX host file system.  Boot2Docker is running as a virtual box vm where the docker images are actually built and containers run.

I have a simple command line interface program that uses docker-java to submit the Dockerfile and related files through the remote api.  All other docker commands are then handled on the VM.

The main change is support for variable substitution in the ADD or COPY resource names.  I included a unit test which runs an example to verify that the substitution works.

I had some problems creating the test Dockerfile in windows in that it contained \r\n's which caused the \r to be attached to the destination file name.  Hopefully as submitted here they are now fixed to have unix line endings of \n only.

The second commit adds the ability to control read time out and if the logging filter should be used.  For my images I was getting way too much binary output during the upload with the LoggingFilter enabled.

I haven't tested the recent changes which changed it to SelectiveLoggingFilter but I think having an option to enable/disable is still valid.