Updated Release: NPOI 2.0 beta 2

Assembly version: 2.0.5

New features
a. Support Scatter chart in XSSF (xlsx)
b. Extract pictures from Excel (xlsx)
c. XWPF becomes stabler than before
d. Able to support xml:space="preserve" attribute
e. Add mono assembly in the release package

Sample changes
a. add new samples like BigGridTest, WritePerformanceTest to test performance
b. add ScatterChart to show how to create Scatter chart
c. add LinkedDropDownList for both XSSF and HSSF
d.

Bug fixes
a. fix shift row issue in XSSFSheet
b. fix performance issue due to XmlSerializer. NPOI is getting rid of XmlSerializer.
c. reading/writing CT_Drawing
d. fix ddd pattern issue in CellDateFormatter
e. Change some common interfaces in NPOI.SS
f. fix OutOfMemory issue in MemoryPackagePart
g. Able to read AbsoluteAnchor, OneCellAnchor, TwoCellAnchor in drawing.xml
h.
i. improve performance for XSSF while creating new rows
For detail, please read https://npoi.codeplex.com/discussions/443655
j. fix name encoding issue of custom properties in HSSF
For detail, please read https://npoi.codeplex.com/workitem/12296
k. Fix exception in HSSFRows.RemoveAllCells