Use mod_rewrite instead of error handlers to redirect to cgimap

Using rewrites is a simpler method then relying on 404 errors and redirecting
Change cgimap error responses to agree with rails port
Make select_(nodes|ways|relations) return ints

This saves calling num_(nodes|ways|relations) if all you've done is the select_ call
Use return value from select_(node|way|relation) for single- and multi-object calls

This saves an index lookup against current_(nodes|ways|relations) for single-object calls and makes it easier for databases without history to handle missing objects
Merge pull request #26 from pnorman/error_report

Change cgimap error responses to agree with rails port
Merge pull request #27 from pnorman/node_visible

Refactor node visibility checks
Accept empty responses in tests

cgimap and the rails port return an empty response for some error
replies (e.g. 404 and 410). Make the test framework accept this.

If a test is expecting content, the nature of the content is tested
in the checks.

Fixes issues introduced in zerebubuth/openstreetmap-cgimap#26
Merge pull request #21 from pnorman/lighttpd_rewrite

Use mod_rewrite instead of error handlers to redirect to cgimap
Merge pull request #29 from pnorman/empty_error_test

Accept empty responses in tests
Don't output lat/lon for deleted nodes

The API changed during the redaction to not output lat/lon for deleted nodes.

This changes cgimap to catch up with that change.

Fixes #30
Merge pull request #31 from pnorman/deleted_coord

Don't output lat/lon for deleted nodes
Bumped version to 0.2.0 for release.
include signal.h to avoid error: main.cpp:468:3: error: use of undeclared identifier 'sigemptyset'
link to boost system to avoid undefined symbol 'boost::system::system_category()'
add aclocal for boost system
Merge pull request #32 from springmeyer/osx-build-fixes

Fixes to compile and link on OS X
Fixed several warnings from -Wall.
Parse options in two phases, allowing multiple backends to define the same option disambiguated by the --backend option value.
Only use pqxx::pqxx_exception with libpqxx 3.0 and later
Specify treatment explicitly for pqxx 2.6