configure.ac rework

- Put libusb and PC/SC check in m4 macros.
- Suppress --disable-pcsclite and --disable-libusb
- Add --with-drivers option: we now could choose which driver to build. without this option a default set is build (ATM all drivers except PN532_UART)

m4/libnfc_drivers.m4

@@ -0,0 +1,64 @@
+dnl Handle drivers arguments list
+
+AC_DEFUN([LIBNFC_ARG_WITH_DRIVERS],
+[
+  AC_MSG_CHECKING(which drivers to build)
+  AC_ARG_WITH(drivers,
+  AC_HELP_STRING([[[[--with-drivers=driver@<:@,driver...@:>@]]]], [Only use specific drivers (default set)]),
+  [       case "${withval}" in
+          yes | no)
+                  dnl ignore calls without any arguments
+                  DRIVER_BUILD_LIST="default"
+                  AC_MSG_RESULT(default drivers)
+                  ;;
+          *)
+                  DRIVER_BUILD_LIST=`echo ${withval} | sed "s/,/ /g"`
+                  AC_MSG_RESULT(${DRIVER_BUILD_LIST})
+                  ;;
+          esac
+  ],
+  [
+          DRIVER_BUILD_LIST="default"
+          AC_MSG_RESULT(default drivers)
+  ]
+  )
+  
+  case "${DRIVER_BUILD_LIST}" in
+    default)
+                  DRIVER_BUILD_LIST="acr122 arygon pn531_usb pn533_usb"
+                  ;;
+    all)
+                  DRIVER_BUILD_LIST="acr122 arygon pn531_usb pn533_usb pn532_uart"
+                  ;;
+  esac
+  
+  DRIVERS_CFLAGS=""
+
+  for driver in ${DRIVER_BUILD_LIST}
+  do
+    case "${driver}" in
+    acr122)
+                  pcsc_required="yes"
+                  DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_ACR122_ENABLED"
+                  ;;
+    pn531_usb)
+                  libusb_required="yes"
+                  DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN531_USB_ENABLED"
+                  ;;
+    pn533_usb)
+                  libusb_required="yes"
+                  DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN533_USB_ENABLED"
+                  ;;
+    arygon)
+                  DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_ARYGON_ENABLED"
+                  ;;
+    pn532_uart)
+                  DRIVERS_CFLAGS="$DRIVERS_CFLAGS -DDRIVER_PN532_UART_ENABLED"
+                  ;;
+    *)
+                  AC_MSG_ERROR([Unknow driver: $driver])
+                  ;;
+    esac
+  done
+  AC_SUBST(DRIVERS_CFLAGS)
+])