Bumping up regression tolerance

Really we should rerun the "gold" results now that we've removed the
inadvertent do-float-calculations-with-doubles code from cea thermo
stuff, but this is easier and works for me.
Bugfix for raw_value_type of MetaPhysicL types
Add ANTIOCH_VERSION_AT_LEAST(major, minor, micro)

Following http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
this macro is usable in situations like
 #if ANTIOCH_VERSION_AT_LEAST(0, 0, 4)
   // Use post 0.0.4 APIs
 #else
   // Use pre 0.0.4 APIs
 #endif
and beats the common
 #define GCC_VERSION (  __GNUC__ * 10000     \
                      + __GNUC_MINOR__ * 100 \
                      + __GNUC_PATCHLEVEL__)
approach since it doesn't require break working with values like 30200.
Merge pull request #17 from RhysU/ANTIOCH_VERSION

Add ANTIOCH_VERSION_AT_LEAST(major, minor, micro)
Fix for compiler warning

Rearranging the macro contents makes those semicolons after the macro
non-redundant
MetaPhysicL-based dR/dT works
MetaPhysicL based sensitivities

Just a test with the arrhenius equation so far, but it's looking like
we're working as expected.
First add to irreversibility, boolean _reversible added to
reactions objects and reading parts. Concerned tests accordingly
modified (true value given)
Setter added
If condition added:
1 - compute the forward rate
2 - if !_reversible, return
3 - calculate and add backward component
Test added, it tests consistency for the reaction N2 + O <=> NO + N
 - kf, kbwd, Keq, rate_fwd, rate_bwd and net_rate are calculated on hand,
 - then net_rate calculated with Antioch
 - rate_fwd calculated by trigging the boolean
then the checks are
 - net rate comparison
 - forward rate comparison
 - (net_rate - forward) v/s rate_bwd comparison
A little cleaning, ElementaryReaction was forward declared twice
Rate coeff are correctly names: if beta != 0, it is Kooij and not
Arrhenius
XML reading for every model
First remark, white spaces added
ModifiedArrhenius label supported, antioch_deprecated added
An antioch_assert forgotten to avoid array overboard
adding latest antioch_assert_less
Merge branch 'master' of https://github.com/libantioch/antioch into parseXML
Necessary changes to library for correct reading:
  - TroeFalloff and LindemannFalloff separated in build_reaction
  - more tests in read_reaction_set_data_xml.h
  - the labels in input files are updated (threeBody -> ThreeBody)
Test added