Log Message:
Update to 1.5.1.  Fix path to where postgis library is actually put.

Bug Fixes

    * #410, update embedded bbox when applying ST_SetPoint,
      ST_AddPoint ST_RemovePoint to a linestring
      (Paul Ramsey)
    * #411, allow dumping tables with invalid geometries
      (Sandro Santilli, for Regione Toscana-SIGTA)
    * #414, include geography_columns view when running upgrade scripts
      (Paul Ramsey)
    * #419, allow support for multilinestring in ST_Line_Substring
      (Paul Ramsey, for Lidwala Consulting Engineers)
    * #421, fix computed string length in ST_AsGML()
      (Olivier Courtin)
    * #441, fix GML generation with heterogeneous collections
      (Olivier Courtin)
    * #443, incorrect coordinate reversal in GML 3 generation
      (Olivier Courtin)
    * #450, wrong area calculation for geography features that cross
      the date line
      (Paul Ramsey)
    * Ensure support for upcoming 9.0 PgSQL release
      (Paul Ramsey)