version 2.3 released

Perl 5.14.4 or newer (was: 5.10.1) is required. The summary view for clouds now also shows their compass direction. The original message and parts information is included in the data for BUFR messages with multiple observations. Processing of SAO AMOS/RAMOS was improved. The new option -P for install.pl can be used to remove the "use lib ..." pragma from scripts. The Makefile was removed. Files are not linked/copied anymore to dedicated web server directories; instead, the Apache configuration uses their original location. A separate Apache configuration is provided for Apache 2.4+.