Skip documentation update if CI build is invoked not on master branch.

Also:
- Setup doxygen configuration on the fly to use minimal theme and to produce SVG instead of PNG.
- Change how the GH_TOKEN is supplied as the GIT version in Travis VM (Ubuntu) does not seem to read the credentials from file store correctly.
- Only generate site documentation after the CI build test has passed.
- Add Ubuntu PPA to install a more recent version of Doxygen.

.travis.yml

@@ -1,7 +1,10 @@
 language: cpp
 compiler: gcc
-before_install: sudo apt-get install -qq libx11-dev libxrandr-dev libasound2-dev libgl1-mesa-dev doxygen graphviz rsync
-script: ./cmake_gcc.sh -DENABLE_64BIT=1 -DENABLE_LUAJIT=1 -DENABLE_LUAJIT_AMALG=1 -DENABLE_SAMPLES=1 -DENABLE_TOOLS=1 -DENABLE_EXTRAS=1 -DENABLE_DOCS_QUIET=1 && cd Build && make
+before_install:
+    - sudo add-apt-repository ppa:george-edison55/precise-backports -y
+    - sudo apt-get update -qq
+    - sudo apt-get install -qq libx11-dev libxrandr-dev libasound2-dev libgl1-mesa-dev doxygen graphviz rsync
+script: ./cmake_gcc.sh -DENABLE_64BIT=1 -DENABLE_LUAJIT=1 -DENABLE_LUAJIT_AMALG=1 -DENABLE_SAMPLES=1 -DENABLE_TOOLS=1 -DENABLE_EXTRAS=1 && cd Build && make
 after_success: rake travis
 env:
   global:

Docs/minimal-header.html

@@ -0,0 +1,5 @@
+---
+layout: page
+title: Documentation
+---
+<div id="top"><!-- do not remove this div, it is closed by doxygen! -->

Rakefile

@@ -1,32 +1,30 @@
 require "rubygems"
 
-# Usage: NOT intended to be used manually (if you insist then try: GIT_NAME=... GIT_EMAIL=... GH_TOKEN=... rake travis)
+# Usage: NOT intended to be used manually (if you insist then try: GIT_NAME=... GIT_EMAIL=... GH_TOKEN=... TRAVIS_BRANCH=master rake travis)
 desc 'Update site documentation to GitHub Pages'
 task :travis do
-  # Skip documentation update if it is a pull request
-  if ENV['TRAVIS_PULL_REQUEST'].to_i > 0
+  # Skip documentation update if it is a pull request or if it is a commit in topic branch
+  if ENV['TRAVIS_PULL_REQUEST'].to_i > 0 or ENV['TRAVIS_BRANCH'] != 'master'
     next
   end
   # Pull or clone
   system 'cd doc-Build 2>/dev/null && git pull -q -r || git clone -q https://github.com/urho3d/urho3d.github.io.git doc-Build'
   # Update credits from Readme.txt to about.md
   system "ruby -lne 'BEGIN { credits = false }; puts $_ if credits; credits = true if /bugfixes by:/; credits = false if /^$/' Readme.txt |ruby -i -le 'BEGIN { credits = STDIN.read }; puts ARGF.read.gsub(/(?<=bugfixes by\n).*?(?=##)/m, credits)' doc-Build/about.md"
+  # Setup doxygen to use minimal theme
+  system "ruby -i -pe 'BEGIN { a = {%q{HTML_HEADER} => %q{minimal-header.html}, %q{HTML_FOOTER} => %q{minimal-footer.html}, %q{HTML_STYLESHEET} => %q{minimal-doxygen.css}, %q{HTML_COLORSTYLE_HUE} => 200, %q{HTML_COLORSTYLE_SAT} => 0, %q{HTML_COLORSTYLE_GAMMA} => 20, %q{DOT_IMAGE_FORMAT} => %q{svg}, %q{INTERACTIVE_SVG} => %q{YES}} }; a.each {|k, v| gsub(/\#{k}\s*?=.*?\n/, %Q{\#{k} = \#{v}\n}) }' Docs/Doxyfile"
+  # Generate doxygen pages
+  system 'cd Build && make doc &>/dev/null'
   # Sync generated doxygen pages (the trailing '/' is significant)
-  # \todo Do this without leaving file changes history in GIT
   system 'rsync -a --delete Docs/html/ doc-Build/documentation'
   # Supply GIT credentials for pushing to GitHub
   system "cd doc-Build && git config user.name '#{ENV['GIT_NAME']}'"
   system "cd doc-Build && git config user.email '#{ENV['GIT_EMAIL']}'"
-  system 'cd doc-Build && git config credential.helper "store --file=.git/credentials"'
-  File.open('doc-Build/.git/credentials', 'w') do |f|
-    f.write("https://#{ENV['GH_TOKEN']}:@github.com")
-  end
-  system "cd doc-Build && git add -A && git commit -q -a -m 'Travis CI automated site documentation update at #{Time.now.utc}.' && git push -q"
+  system "cd doc-Build && git remote set-url --push origin https://#{ENV['GH_TOKEN']}@github.com/urho3d/urho3d.github.io.git"
+  system "cd doc-Build && git add -A && git commit -q -a -m 'Travis CI: site documentation update at #{Time.now.utc}.' && git push -q"
   # Debug start
   system "echo GIT_NAME='#{ENV['GIT_NAME']}'"
   system "echo GIT_EMAIL='#{ENV['GIT_EMAIL']}'"
-  system "GH_TOKEN='#{ENV['GH_TOKEN']}' echo GH_TOKEN=${GH_TOKEN:0:5}"
-  system 'cd doc-Build && git config --list'
+  system "echo GH_TOKEN=`echo '#{ENV['GH_TOKEN']}' |cut -c1-5`"
   # Debug end
-  File.delete 'doc-Build/.git/credentials'
 end