Solve issue OTL#27: Set double slider limits to system float limits

This fix lets the user write slider limits that are higher than 10k or lower than -10k. The min and max spinboxes become slightly larger due to the larger limits. It would be a good feature to set a fixed spinbox length to solve this.

src/rqt_ez_publisher/widget/double_value_widget.py

@@ -1,7 +1,7 @@
 from python_qt_binding import QtCore
 from python_qt_binding import QtWidgets
 import value_widget
-
+from sys import float_info as float_info
 
 class DoubleValueWidget(value_widget.ValueWidget):
 
@@ -36,15 +36,15 @@ def slider_changed(self, val):
 
     def setup_ui(self, name):
         self._min_spin_box = QtWidgets.QDoubleSpinBox()
-        self._min_spin_box.setMaximum(10000)
-        self._min_spin_box.setMinimum(-10000)
+        self._min_spin_box.setMaximum(float_info.max)
+        self._min_spin_box.setMinimum(-float_info.max)
         self._min_spin_box.setValue(self.DEFAULT_MIN_VALUE)
         self._slider = QtWidgets.QSlider(QtCore.Qt.Horizontal)
         self._slider.setTickPosition(QtWidgets.QSlider.TicksBelow)
         self._slider.valueChanged.connect(self.slider_changed)
         self._max_spin_box = QtWidgets.QDoubleSpinBox()
-        self._max_spin_box.setMaximum(10000)
-        self._max_spin_box.setMinimum(-10000)
+        self._max_spin_box.setMaximum(float_info.max)
+        self._max_spin_box.setMinimum(-float_info.max)
         self._max_spin_box.setValue(self.DEFAULT_MAX_VALUE)
         self._lcd = QtWidgets.QLCDNumber()
         self._lcd.setMaximumHeight(self.LCD_HEIGHT)