Enable travis-ci tagged builds

To have binaries with version string set automatically and remove
the temporary hacks.
[skip ci]

.travis.yml

@@ -1,5 +1,7 @@
 branches:
-- master
+  only:
+  - master
+  - /^[vV]\d+\.\d+(\.\d+)?(-\S*)?$/
 os:
 - osx
 - linux

travis/linux/before_script.sh

@@ -5,9 +5,7 @@ export PATH=/opt/qt59/bin:$PATH
 cp qwt/qwtconfig.pri.in qwt/qwtconfig.pri
 cp src/gcconfig.pri.in src/gcconfig.pri
 # Define GC version string, only for tagged builds
-#if [ -n "$TRAVIS_TAG" ]; then echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri; fi
-# Temporary hack to get version string without a new tag
-echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri;
+if [ -n "$TRAVIS_TAG" ]; then echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri; fi
 # user WEBENGINE
 echo DEFINES += NOWEBKIT >> src/gcconfig.pri
 # Trusty needs C99 mode to enable declarations in for loops

travis/osx/before_script.sh

@@ -22,9 +22,7 @@ cd ..
 cp qwt/qwtconfig.pri.in qwt/qwtconfig.pri
 cp src/gcconfig.pri.in src/gcconfig.pri
 # Define GC version string, only for tagged builds
-#if [ -n "$TRAVIS_TAG" ]; then echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri; fi
-# Temporary hack to get version string without a new tag
-echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri;
+if [ -n "$TRAVIS_TAG" ]; then echo DEFINES += GC_VERSION=VERSION_STRING >> src/gcconfig.pri; fi
 echo DEFINES += NOWEBKIT >> src/gcconfig.pri
 sed -i "" "s|#\(CONFIG += release.*\)|\1 static |" src/gcconfig.pri
 sed -i "" "s|#\(QMAKE_LRELEASE\).*|\1 += /usr/local/opt/qt5/bin/lrelease|" src/gcconfig.pri