Use udunits package for units conversions

Changed the include for udunits to #include <udunits2.h> to work
on all platforms.  Added the include directory /usr/include/udunits2
for Linux.

refs #231

include/trick/UdUnits.hh

@@ -2,7 +2,7 @@
 #ifndef UDUNITS_HH
 #define UDUNITS_HH
 
-#include <udunits2/udunits2.h>
+#include <udunits2.h>
 #include <string>
 
 namespace Trick {

include/trick/swig/swig_int_templates.hh

@@ -7,7 +7,7 @@
 #define SWIG_INT_TEMPLATES_HH
 
 #include "trick/UdUnits.hh"
-#include <udunits2/udunits2.h>
+#include <udunits2.h>
 
 template< class S , typename T > static int convert_and_set( T & output , void * my_argp , std::string to_units ) {
     int ret = 0 ;

share/trick/makefiles/config_Linux.mk

@@ -64,3 +64,6 @@ ifeq "" "c++11"
 TRICK_ADDITIONAL_CXXFLAGS += -std=c++11 -D_HAVE_STL_RANDOM
 endif
 
+# Additional include directory for udunits.
+TRICK_ADDITIONAL_CXXFLAGS += -I/usr/include/udunits2
+

trick_source/codegen/Interface_Code_Gen/FieldDescription.hh

@@ -6,7 +6,7 @@
 #include <map>
 #include <stdint.h>
 
-#include <udunits2/udunits2.h>
+#include <udunits2.h>
 
 #include "ConstructValues.hh"
 #include "clang/Basic/Specifiers.h"

trick_source/codegen/Interface_Code_Gen/makefile

@@ -43,6 +43,7 @@ CXXFLAGS += -std=c++11
 # Fedora 21 adds -ledit as a system lib, but it isn't installed, or required.
 CLANGLIBS += $(filter-out -ledit,$(shell $(LLVM_HOME)/bin/llvm-config --system-libs))
 endif
+CXXFLAGS += -I/usr/include/udunits2
 endif
 
 ifeq ($(TRICK_HOST_TYPE),Darwin)

trick_source/trick_swig/swig_convert_units.cpp

@@ -1,7 +1,7 @@
 
 #include <Python.h>
 #include <iostream>
-#include <udunits2/udunits2.h>
+#include <udunits2.h>
 
 #include "trick/Unit.hh"
 #include "trick/UdUnits.hh"

trick_source/trick_swig/units_attach.i

@@ -6,7 +6,7 @@
 
 %inline %{
 #include <frameobject.h>
-#include <udunits2/udunits2.h>
+#include <udunits2.h>
 #include "trick/swig/swig_double.hh"
 
 std::string map_trick_units_to_udunits( std::string orig_units ) ;