Static graphs: Add "Horizontal Bar Graphs" for more efficient data visualization

[julienmoumne]

Horizontal bar graph will solve the third issue mentioned in #2704 : Show more labels on X Axis

See attached file for POC.

[julienmoumne]

Attachment: POC Horizontal Bar Graph - getCountry
getCountry.png

[julienmoumne]

(In [5582]) * fixes #2706, #2828, #2704, refs #1721, #2637, #2711, #2318, #71 : horizontal static graph implemented

• fixes Static Graph: better graphs when date range period parameter #2788, refs Metadata improvements to generate static graph image URL #2670, ImageGraph: export reports as graph #1721, #2637, #2711 : default graph type logic moved to ImageGraph API, improved date/period logic, new parameter graphs_default_period_to_plot_when_period_range
• fixes Graphs should support Unicode characters & other improvements #2704, graph image cutoff first digits when Y axis has decimals #2804, refs ImageGraph: export reports as graph #1721 : pChart updated to 2.1.3, pChart code removed from Piwik code, OOP refactoring, support for unifont.ttf if present in ImageGraph/fonts, testAllSizes now uses report metadata ImageGraphUrl
• refs Plugin to provide PDF export of data #5491 : space between report title and report table reduced to avoid page overflow
• refs ImageGraph: graphs should display % values #2829 : TODO display percentages
• r5544, r5547, r5549 merged

[mattab]

see also the same feature request for Javascript Graphs, which will be a killer visualization tool: #3109