Studying efficient algorithms to populate Dixon's sets B, R.

Starting the development of Dixon's attack, and evaluating the efficieency of
some algorithms for the generation of the rᵢ.
Merge branch 'master' into feature/wiener
Documenting breifly what's the Wiener Attack about.

Enounce Wiener's theorem, more or less how it's written on twnty years; using
doxyigen style.
(assumed) non-working version of Dixon's Attack.

Saving with the latest changes. This code has not been tested, and that's more
like pseudocode than real-code.
Merge branch 'master' into fix/posix
Merge branch 'feature/dixon' into fix/posix
Creating qstrings.c file, holding utilities for working with strings.

First step torwars a include "qa/questions/foo.h".
Moving is_vzero() from Dixon into another file, which could be used as well for
other attacks.
Refactoring: moving all header files into include/ subdirs.

Creating include/ in src/, and then a root of directories such that
everything belonging to qa now stays inside the qa/directory. Eventually,
questions files can be found in qa/questions
XXX. shall questions.h be found in qa/ or qa/questions? :S
Select questions/tests/ as unique pathname for unittests, and removing /test.

Just some shitty cleanup that shall have been done long ago.
Whoa! Unittests.

Unittesting using automake's very kool™ `make check`, and adapting to test_qstrings.
Creating qarith.c, as module for arithmetic operations with bignums.

Moving some code from wiener's attack inro qarith, in order to provide easy
access to square root operations also for other attacks.
Doing this, I also moved the unittests for this function to test_qarith.c, and
added it to Makefile.am as test target.
Test test_qa_sock.c

NO idea how it disappeared from the tree, or whether it haz ever been there.
Merge branch 'feature/wiener' into fix/posix
make check available also for test_qa and test_qa_sock.

Something strange, test_qa is failing here. Checking later.
Improving gen program, using getopt() and testing it with a trivial script.

XXX. The syntax gives as helper in usage is probably wrong, shall read POSIX
standard.
Modifying gen program to be used for generating test private and public keys.
Simplyfyiing Makefile.am for tests.

using a proper variable for just-built unittests whenever possible.
Restoring test_qa test_qa_sock to a working state.

Adding dummy.crt which wasn't yet on the source tree, and using relative paths
instead of full path when loading it.
Fixing makefile error due to which the wrong main() function was being taken.
Refactoring: adding ask_rsa() to question_t as callback for rsa keys specifically.

Changin this API was made just to avoid the annoyng preface of
get_pubkey->rsa. And being faster whenever testing.
Enabling tests with automake.
Testing "gen priv" command.
New "-a" option, for slecting a specific attack.

This adds a new command-line option, for selecting the attacks, and improves the
questions enviroment. Specifically,
* Adds a new .pretty_name string to trettify name;
* Adds documentation for structures qa_question_t
* Delegates attacks to a  new function qa_dispose().