Removed ParserItemTemplate.hpp for install list
Removed CJSON check to top level CMakeLists.txt file
Changed include path to cJSON
Added function install_headers() which will retain header prefix path
Moved enable_language( C ) to top level CMakeLists.txt
Merge branch 'master' into cmake-package-config
Changed Findcjson.cmake to use OPM_PARSER_ROOT as prefix - if CJSON_ROOT has not been set
Added install-headers function + opm-parser-prereqs.cmake
Change unintended compile-time polymorphism to dynamic

equals(ParserIntItem&) has a different signature than equals(ParserItem&),
thus the former method does *not* overload the latter. Virtual just means
then only means that you have created a *new* entry in the v-table. If
you call equals through a pointer/reference to the base class ParserItem,
the defined method in the derived class is not called, and we miss out the
test for the equal default value.

Instead, we should take an argument of the base type and use a dynamic
cast to the derived type. If this downcast fails, then they are not equal;
otherwise we have gotten ourselves a pointer to get the properly typed
default value.

We must use pointers instead of references; if we cast to a reference,
a bad_cast exception is thrown if the expression is not in the proper
type hierarchy.
Merge pull request #36 from joakim-hove/cmake-package-config

Cmake package config
Added test for compile time polymorphism
Merge pull request #37 from rolk/037_virt

Change unintended compile-time polymorphism to dynamic
Merge remote-tracking branch 'upstream/master' into test-compile-time-polymorphism
Merge pull request #41 from joakim-hove/test-compile-time-polymorphism

Test compile time polymorphism
Merged with upstream/master
Added test for DATES and TSTEP keyword respectively in TimeMap