grid properties: add support for the NTG keyword

Whoever came up with that keyword deserves a spanking because its
semantics are adapting thickness of the grid layers using the rock
properties without modifying the grid (and thus the output is not
showing what is actually used). As I understood that whole affair,
this is also done incorrectly, because the flow is not distorted in
depth direction but this the permeability should be divided by the NTG
values as the fluids seep through the thinner layers more quickly...

Anyway, we have to implement it, so here we go.
Added new enum to enumerate the different face directions.
Added transMult container - which only returns 1.0
Added TransMult object to EclipseState
Merge pull request #244 from joakim-hove/TransMultContainer

Trans mult container
Merge pull request #245 from andlaus/add_ntg_gridproperty

grid properties: add support for the NTG keyword
Fixed trivial typo.
Typo in install target
Added SWATINIT as supported grid property.
Changed from semicolon to comma, to fix compilation failure
Merge pull request #246 from flikka/SWATINIT-semicolon-bug

Changed from semicolon to comma, to fix compilation failure
fix build

*grr* spurious comma! Though I'm wondering a bit why it compiled on my
 machine yesterday...
Merge pull request #247 from andlaus/fix_build

fix build
syncronize Findopm-parser.cmake with the opm-core version

the ERT libraries and headers were missing and a few other minor
cleanups. see https://github.com/OPM/opm-core/pull/601 for details.
add the boost::regex library as a prerequisite

this is required for regex-matching keywords. Once GCC 4.9 is the
minimum compiler version to be supported, this can be dropped in favor
of std::regex ...
add boost::regex as a prerequisite to the opm-parser build system
allow keywords to match regular expressions as their deck name

the RE used is specified via the "deck_name_regex" in the JSON file of
the respective keyword. A deck name is assumed to match a given parser
internal keyword if the deck name is valid and if it is either in the
list specified by the "deck_names" entry or if it matches the regular
expression.

This functionality is useful to implement the well probes for the
tracers as well as replacing the current "wild card keyword"
implementation which only allows a star as a suffix.
allow underscores in deck names and disallow sharps

underscores are used by a few of the summary specifier keywords
(e.g. BPR_X), but after closer inspection '#' symbols are not.
fix typo

the JSON name of DEPTH keyword was "DEPTHZ". since "DEPTH" is an
E100 keyword, this is most likely a mistake...
change the TVDP keywords to use regular expressions instead of wildcards