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