new programmatic example

(cherry picked from commit 42ae56b25e8c6ed9c2e846d8aac054f4010d0f3b)
fix issue #6 (+ remove useless required module)

(cherry picked from commit daf2c79ca76a7aadcff79dd2488cf925fac83e3d)
fix #5

(cherry picked from commit 01c7235c3d1419f009aec2721f42243750d0c52b)
fix #1

(cherry picked from commit 48f1469c70ca96a6e3af8196abadcdec7d7262d6)
fix #8

(cherry picked from commit f746b57048b5e90c64f137b2e47f1d34fe82b514)
remove a useless refreshRendering

(cherry picked from commit 4053db268bb55fffdf440ec30ba3847d26aa6576)
gaugebase.value wraps the value of the first indicator named indicator instead of the first indicator

(cherry picked from commit 2a063b2e1bb76979fcdb15ae9c9fd49a3d9c7a02)
use _set instead of direct assignment of value on gaugebase

(cherry picked from commit 5fc550241f51ea243425ae58f47eb16b0b8087b3)
add a contributing file that will show up when opening a pull request on this repository

(cherry picked from commit 90c11f46f6b5293d37fd4f53c7b36eb8e9039d4c)
copyright updated to 2013

(cherry picked from commit 706a884909971eb6ec8d06e3d2f9d568db5ac640)
improve doc, cleanup code

(cherry picked from commit 7e31c571956d026637774a073f874a0398fb430e)
fix #13: a new semi circular example

(cherry picked from commit 2f74637a68ef8421b4fcf4e45f31a76efdeff37e)
remove some useless code

(cherry picked from commit 7076e377d8cf840c33477946e7e2c3277263d134)
fix #15

(cherry picked from commit ca346ef41132c6a2783f344570f9406e2b1808f8)
fix #16

(cherry picked from commit b2a683146c735c19d47d5253876950c9fcf4cd5d)