Remove old lineChart class, add LineChart and alias

From User's point of view no a difference
Remove old pieChart class, add PieChart and alias

From User's point of view no a difference
Remove old lineWithFocusChart add LineWithFocusChart

Add alias, such that from user point of view there
is no difference
Replace multiBarHorizontalChart with the new class

And add alias ...
Replace old with new class and alias
Remove old unused templates

These templates are no longer used, since
the new class uses the newer templates.
Renamed infra.html to html, update content.html
Remove old class, add new class alias
Remove old cumulativeLineChart add alias for new class
Replace old class scatterChart with alias to new class
Replace old class with an alias to the new class
Replace multiBarChart with alias to new class
Remove old linePlusBarWithFocusChart and relace with alias

Also remove unused template
Add jinja Environment and template loader to NVD3Chart

Thus, there is no need to initialize the Environment and
Loader with every child class.
Replace FileSystemLoader with PackageLoader

This is more elegant. We can add FileSystemLoader
later when we allow users to customise their templates
more easily ...
Also removed unused imports
Remove duplicate targets in Makefile
Remove EVIL eval call !!!
Merge pull request #73 from oz123/templates_clean

Templates clean
give credits to @oz123 for maintaining python-nvd3
Update .travis.yml

Fix missing dependencies