Firebird support in Sphinx

This patch adds Firebird support into Sphinx full-text search engine 
(www.sphinxsearch.com)

1. Patch contains 3 parts
  - firebird.linux.patch	changes to make process on Linux
  - firebird.win.patch		changes to Windows build system (MSVC8)
  - firebird.src.patch		changes to Sphinx sources


2. sphinx-0.9.8.1.Firebird.Win32.zip contains binaries for Win32
  built with this patch. Executables linked with fbclient.dll

   sphinx-0.9.8.1.Firebird.Win32.USE_64BIT.zip contains binaries for Win32
  built with this patch and USE_64BIT defined. This is not a x64 build !
  This is just an ability to use unsigned 64-bit integers as document identifiers
  instead of signed 32-bit in "normal" build.


3. sphinx.conf
  - in the "source" section for Firebird data sources you need to
    set "type" parameter value to "firebird" :

	type	= firebird

  - "sql_host" and "sql_port" parameters are ignored, use "sql_db"
    value to specify full connection string to Firebird database.
    Connection string is build by Firebird rules and passed into
    isc_attach_database() call as is :

	sql_db	= c:\...\data.fdb
    or
	sql_db	= host/port:c:\...\data.fdb

  - two new Firebird-specific parameters introduced : 
    "sql_role"		to specify connection role
    "sql_charset"	to specify connection character set

  - Firebird have no native support for unix timestamp's. If you need 
    it, you may use following expression (starting from Firebird 2.1) 
    to calculate unix timestamp :

	DATEDIFF(SECOND, timestamp '01-01-1970', <field name>)


Happy testing !

Pierre Yager,
Vlad Khorsun, hvlad at users sourceforge net