investigating 'markup' approach to simplify the query
switched to local shared_ptr + added markup interface

markup interface: basic dynamic class interface which allows to
use a certain 'markup' for queries. this enables external developers
to replace rather awkwardly looking XPath expressions like
  string Si_bandgap_query = "/materials/material[id=\"Si\"]/parameter[name=\"bandgap\"]/value/text()";
with
  string result = matlib->query("Si/bandgap");

we will see how this works out ..
playing around with the 'localized' markup

this markup should translate from a much simplified user query string
to the actual XPath expression.
what can be assumed? and what not? need more thinking on this
quicksafe: moving to 'proxy' approach

instead of letting the library hold the layout specific part,
the layout specific object shall hold the library, becoming a 'proxy' so to say.

develoeprs can use the library object to do native xpath queries _but_
they can setup proxy objects with their 'own' language, respecting their
own xml markup for instance. within the proxy object, the specialized/localized
query string has to be transformed into a valid xpath query.
let's see ..
first prototype of a 'viennastar' proxy implemented

this proxy will allow our team to simplify our material queries
based on a specific viennastar XML layout. each proxy holds
a shared pointer to the material library backend, thus
developers can actually have several proxies operating on the same
backend.

also, did some cleanup (i.e. removed obsolete files and code)

now off to revisiting the central library object
fixed headers and include comments
removed clean script + made 'boost' a requ in README

currently we need boost for string operations, however, we will get rid of
it soon, at least as an external dependency
added two examples: native and proxy

where the first shows how to perform native (i.e. xpath) queries,
the second discusses how to use the convenience proxy layer
minor fixed in the README
removed boost depend from pugixml.cpp+init tests

implemented 'trim' function in utils/string.hpp

started test environment with a string tests
implemented string split algorithm + test

replaces boost::algorithm::split
implemented 'replace_first' algo -> we are Boost-free now
updated readme

removed boost dependency and added examples/testing section
added native and proxy tests

for now, using asserts to 'test' the results of the internal mechanisms
not optimal, as, for instance, assert crashes on the first 'error' and does not proceed with the testing