Uninstall description + launch gpx.exe dir

The nuspec description gets put in the Windows control panel as the
program name. Made it shorter to be more explicable, perhaps we should
go shorter yet.

In anticipation of not necessarily having gpx.exe on the path (plus
controlling for multiple versions of gpx.exe), launch gpx.exe from the
same folder as gpxui.exe.

gpx.nuspec

@@ -9,7 +9,7 @@
     <projectUrl>http://github.com/markwal/GpxUi</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/markwal/GpxUi/master/gpx.ico</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
-    <description>GPX is a post processing utility for converting gcode output from 3D slicing software to x3g files for standalone 3D printing on Makerbot printers.</description>
+    <description>GPX converts .gcode to .x3g for 3d printing</description>
     <copyright>Copyright 2013-2015, portions copyright 2008, all rights reserved</copyright>
     <tags>gcode x3g makerbot</tags>
   </metadata>

rungpx.cpp

@@ -1,6 +1,7 @@
 #include "rungpx.h"
 #include "ui_rungpx.h"
 
+#include <QDir>
 #include <QProcess>
 #include <QMessageBox>
 #include <QPushButton>
@@ -57,7 +58,8 @@ void RunGpx::ReadStdOut()
 
 void RunGpx::Translate(const QString& sInputName, const QString& sOutputName)
 {
-    QString sApp = QLatin1String("gpx.exe");
+    QDir dir(QApplication::instance()->applicationDirPath());
+    QString sApp = dir.absoluteFilePath(QLatin1String("gpx.exe"));
     QStringList slArgs;
     slArgs << QLatin1String("-v") << sInputName << sOutputName;