make NEWS.md adhere to pkgdown standards

Release dates removed from version heading in NEWS.md.
They are auto-added as subheader by pkgdown.

NEWS.md

@@ -46,24 +46,24 @@
   * saveAsExcel to save grids as Microsoft Excel files
   * replace xlsx by openxlsx to import Excel files to get rid of JRE dependency
 
-# OpenRepGrid 0.1.10 (released February 24, 2017) 
+# OpenRepGrid 0.1.10
 
   * indexDilemma: improved implicative dilemmas (thanks to Alejandro García, (#24, @j4n7)
   * changelog file as place for documenting changes removed. All changes now in NEWS
 
-# OpenRepGrid 0.1.9 (released September 06, 2014) 
+# OpenRepGrid 0.1.9
 
   * align parameter added to cluster
   * importTxt will now erase empty lines
   * changed default settings for implicative dilemmas
   * dependency on xlsx removed (issue #15)
 
-# OpenRepGrid 0.1.8 (released June 13, 2013)
+# OpenRepGrid 0.1.8
 
   * importGridstat can now import multigrid files
   * bug fix in importTxt: negative values are read in again
 
-# OpenRepGrid 0.1.7 (released May 25, 2013)
+# OpenRepGrid 0.1.7
 
 * print functions for most grid indexes added, former output argument no longer exists
 * settings function added. Settings can now be modified, saved and loaded
@@ -75,38 +75,35 @@
 * importTxt: ratings and range can now have an arbitrary number of blanks or tabs between the values. The characters - (minus) and ? (question mark) are read in as missing values (NA). The file extensions .TXT (capitals) is now recognized
 * clusterBoot added:implementation of pvclust functions
 
-# OpenRepGrid 0.1.6 (released April 5, 2012)
+# OpenRepGrid 0.1.6
 
 * biplot functions fixed. They work again.
 
-# OpenRepGrid 0.1.5 (released July 17, 2011)
-
-* First public version release version available on CRAN.
-
-# OpenRepGrid 0.1.5 (2011-17-07) 
+# OpenRepGrid 0.1.5
 
+* First release version available on CRAN.
 * method dim to return size of a grid. A simple wrapper around getNoOfConstructs and getNoOfElements
 * package description updated
 * prob argument in distanceXXX functions added
 * bug in makeRepgrid corrected: ratings now read by row
 
-# OpenRepGrid 0.1.4 (2011-05-31) 
+# OpenRepGrid 0.1.4
 
 * demo added
 * bug corrected in importScivesco
 * changed package description
 * prob parameter: randomGrid(s), quasiDistributionDistanceSlater (dev)
 * distanceNormalized
 
-# OpenRepGrid 0.1.3 (2011-05-27)
+# OpenRepGrid 0.1.3
 
 * permuteConstructs (dev)
 * update openrepgrid-internal
 * permuteGrid (dev)
 * update zzz
 * corrected COLLATION order
 
-# OpenRepGrid 0.1.2 (2011-05-21) 
+# OpenRepGrid 0.1.2
 
 * polishing of console output for several functions:
 * constructCor
@@ -117,7 +114,7 @@
 * alignByLoadings
 * some others might have been changed (undocumented)
 
-# OpenRepGrid 0.1.1 (2011-05-15) 
+# OpenRepGrid 0.1.1
 
 New Features
 
@@ -133,14 +130,14 @@ Internal changes
 * getElementNames2
 * formatMatrix
 
-# OpenRepGrid 0.1.0 (2011-05-08) 
+# OpenRepGrid 0.1.0
 
 New Features
 
 * Slater distance
 * Hartmann distance
 
-# OpenRepGrid 0.0.9 (2011-05-05) 
+# OpenRepGrid 0.0.9
 
 New Features
 
@@ -152,23 +149,23 @@ New Features
 * frames for biplot3d
 * intensity index
 
-# OpenRepGrid 0.0.8 (2011-05-03) 
+# OpenRepGrid 0.0.8
 
 New Features
 
 * construct lines in drawBiplot2d
 * saveAsTxt
 * new examples added
 
-# OpenRepGrid 0.0.7 (2011-04-28) 
+# OpenRepGrid 0.0.7
 
 New Features
 
 * updated documentation files
 * changes in addVarianceExplainedToBiplot2d
 * alignByIdeal
 
-# OpenRepGrid 0.0.6 (2011-04-27) 
+# OpenRepGrid 0.0.6
 
 New Features
 
@@ -179,20 +176,20 @@ New Features
 * biplotSlater3d
 * home
 
-# OpenRepGrid 0.0.5 (2011-04-20) 
+# OpenRepGrid 0.0.5
 
 New Features
 
 * center
 * normalize
 
-# OpenRepGrid 0.0.4 (2011-03-03) 
+# OpenRepGrid 0.0.4
 
 New Features
 
 * not documented
 
-# OpenRepGrid 0.0.3 (2011-03-03) 
+# OpenRepGrid 0.0.3
 
 New Features:
 
@@ -210,10 +207,10 @@ New Features:
 * constructRmsCor
 * constructPca
 
-# OpenRepGrid 0.0.2 (2010-01-06) 
+# OpenRepGrid 0.0.2
 
 * Several new Features
 
-# OpenRepGrid 0.0.1 (2010-12-03) 
+# OpenRepGrid 0.0.1
 
-* First version
+* First version (2010-12-03)