remove last references to boost_iostreams dependency

INSTALL

@@ -63,7 +63,6 @@ First, here is a quick list of the required software dependencies:
     - thread
     - filesystem
     - regex (built against libicu >= 4.2)
-    - iostreams
     - python - required only for python bindings (see below)
 - libicu >= 4.2 - International Components for Unicode
 - libpng - PNG Graphics

SConstruct

@@ -1042,7 +1042,6 @@ if not preconfigured:
         ['system', 'boost/system/system_error.hpp', env['HAS_BOOST_SYSTEM']],
         ['filesystem', 'boost/filesystem/operations.hpp', True],
         ['regex', 'boost/regex.hpp', True],
-        #['iostreams','boost/iostreams/device/mapped_file.hpp',True],
         ['program_options', 'boost/program_options.hpp', False]
     ]
         

plugins/input/geos/SConscript

@@ -35,7 +35,6 @@ geos_src = Split(
         )
 
 libraries = [env['PLUGINS']['geos']['lib']]
-libraries.append(['boost_iostreams%s' % env['BOOST_APPEND']])
 
 if env['PLATFORM'] == 'Darwin':
     libraries.append('mapnik2')

plugins/input/shape/SConscript

@@ -37,7 +37,7 @@ shape_src = Split(
   """
         )
 
-libraries = [] #['boost_iostreams%s' % env['BOOST_APPEND']]    
+libraries = []
 
 if env['PLATFORM'] == 'Darwin':
     libraries.append('mapnik2')

utils/ogrindex/SConscript

@@ -37,9 +37,8 @@ source = Split(
 headers = ['#plugins/input/ogr'] + env['CPPPATH'] 
 
 boost_program_options = 'boost_program_options%s' % env['BOOST_APPEND']
-boost_iostreams  = 'boost_iostreams%s' % env['BOOST_APPEND']
 boost_filesystem = 'boost_filesystem%s' % env['BOOST_APPEND']
-libraries =  [boost_program_options,boost_iostreams,boost_filesystem,env['PLUGINS']['ogr']['lib'],'mapnik2']
+libraries =  [boost_program_options,boost_filesystem,env['PLUGINS']['ogr']['lib'],'mapnik2']
 
 boost_system = 'boost_system%s' % env['BOOST_APPEND']