Eliminate new line characters in worksheet formulas. They can appear if the user explicitly enters the formula over multiple lines.

EPPlus/ExcelCellBase.cs

diff --git a/EPPlus/ExcelCellBase.cs b/EPPlus/ExcelCellBase.cs
index 529365c..f5694c1 100644
--- a/EPPlus/ExcelCellBase.cs
+++ b/EPPlus/ExcelCellBase.cs
@@ -198,6 +198,7 @@
             string ret = "";
             string part = "";
             char prevTQ = (char)0;
+            value = value.Replace("\n", "");  // Eliminate new line characters in the formula
             for (int pos = 0; pos < value.Length; pos++)
             {
                 char c = value[pos];