Added initial support for --next/-: which will be used to replace the
rather confusing : command line operation what was used for the URL
specific options prototype.
In preparation for separating the global config options from the per
operation config options, reworked the list engines code to not use a
member variable in the Configurable structure.
1 - str2offset() no longer accepts negative numbers since offsets are by
nature positive.
2 - introduced str2unum() for the command line parser that accepts
numericals which are not supposed to be negative, so that it will
properly complain on apparent bad uses and mistakes.
Bug: http://curl.haxx.se/mail/archive-2012-07/0013.html
Configuration files such as curl_config.h and all config-*.h no longer exist
nor are generated/copied into 'src' directory, now these only exist in 'lib'
directory from where curl tool sources uses them.
Additionally old src/setup.h has been refactored into src/tool_setup.h which
now pulls lib/setup.h
The possibility of a makefile needing an include path adjustment exists.
