Add VO modules and GVOClient.hpp header file.
Add VO module for Virtual Observatory protocol support.
Initial version of VO client.
Add VO module for Virtual Observatory support.
Add VO test for testing of Virtual Observatory module classes.
Initial version
Ignore VO test executable
Implement find_hub() and hashub() methods.

The find_hub() method searches for a Hub and retrieves the relevant tokens. So far, no GammaLib own Hub is started if no Hub has been found.

The hashub() method checks if all mandatory Hub tokens have a value. No value check is done.
Implement connect_hub() method.
Implement parsing of text string.

The parse() method now either parses a file or a text string, depending on whether a valid file pointer or text string is provided. This option is now used in the GXml(const std::string& xml) constructor that will interpret the argument as either a text string or a file name. The interpretation is done on basis of the 5 first characters. If the string starts with "<?xml" the string is an XML document, otherwise it will be interpreted as a filename.
Implement sending of static metadata.

Some static metadata is sent to the Hub. Ultimately, the metadata that should be sent should be defined by the client application.
Add text methods for attribute access.
Add m_name, m_host and m_port members and implement new socket handling.

The Hub host and port strings are now stored in the members m_host and m_port. This prevents recomuting them when connecting to the Hub. Also the client name is now stored. It will be sent as the minimum required metadata (although it is formally not required).

The socket handling now follows the recommandations of Beej's Guide to Network Programming.
Add unregister_from_hub() method and rename some proteced methods.
Implement disconnect() method.

Implement unregistering from the Hub. For this purpose the unregister_from_hub() method has been created that sends the appropriate class to the Hub. Some of the other protected methods have been renamed to be more explicit.

Added also #include <fcntl.h> to make compatible to Fedora.
Test client disconnetion.
Add information about new VO module.
Adapt print() method to the case that no Hub has been found.
Include <unistd.h> needed for close() function on Fedora.

The <fcntl.h> was not the correct header ...