[PLAT-6852] Implemented exponential interpolator
[PLAT-6852] Modified javadoc
[PLAT-6856] removing deprecated under OG-Analytics/src/main/java/com/opengamma/analytics/financial/credit/creditdefaultswap/
[PLAT-6852] Simplified formulas, added piecewise function test
Merge pull request #271 from OpenGamma/REQS-666/PLAT-6856

[PLAT-6856] Stage 1: Removing deprecated under CDS umbrella
[PLAT-6856] remove deprecated and associated under OG-Analytics/src/main/java/com/opengamma/analytics/financial/credit/obligor/
Merge pull request #272 from OpenGamma/REQS-666/PLAT-6856-1

[PLAT-6856] Stage 2: Remove deprecated related to obligor
[PLAT-6856] remove classes named *Deprecated*
Merge pull request #273 from OpenGamma/REQS-666/PLAT-6856-2

[PLAT-6856] Stage 3: Remove classes named `*[d,D]eprecated*`
Merge pull request #270 from OpenGamma/topic/PLAT-6852

[PLAT-6852] Implemented exponential interpolator
[PLAT-6837} Fix spelling mistake
Merge branch 'develop' into wip/REQS-563