update readline library to last version (6.3)
Added pecl_http support
centralize location of extension dir
forgot one extension install dir replacement
Merge remote-tracking branch 'origin/5_4_mountainlion' into 5_4_snowleopard

* origin/5_4_mountainlion:
  forgot one extension install dir replacement
  centralize location of extension dir
  Added pecl_http support
  update readline library to last version (6.3)