Fix typos in comments, documentation and strings (#1615)

All of them were found using codespell.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

Data/PostgreSQL/include/Poco/Data/PostgreSQL/PostgreSQL.h

@@ -28,7 +28,7 @@
 // from a DLL simpler. All files within this DLL are compiled with the ODBC_EXPORTS
 // symbol defined on the command line. this symbol should not be defined on any project
 // that uses this DLL. This way any other project whose source files include this file see
-// ODBC_API functions as being imported from a DLL, wheras this DLL sees symbols
+// ODBC_API functions as being imported from a DLL, whereas this DLL sees symbols
 // defined with this macro as being exported.
 //
 #if defined(_WIN32) && defined(POCO_DLL)

Data/PostgreSQL/include/Poco/Data/PostgreSQL/StatementExecutor.h

@@ -58,7 +58,7 @@ public:
 		/// Prepares the statement for execution.
 
 	void bindParams(const InputParameterVector& anInputParameterVector);
-		/// Binds the params - REQUIRED if the statment has input parameters/placeholders
+		/// Binds the params - REQUIRED if the statement has input parameters/placeholders
 		/// Pointer and list elements must stay valid for the lifetime of the StatementExecutor!
 
 	void execute();

Data/PostgreSQL/src/SessionImpl.cpp

@@ -199,7 +199,7 @@ SessionImpl::begin()
 void
 SessionImpl::commit()
 {
-	// Not an error to issue a COMMIT without a preceeding BEGIN
+	// Not an error to issue a COMMIT without a preceding BEGIN
 	_sessionHandle.commit();
 }
 
@@ -207,7 +207,7 @@ SessionImpl::commit()
 void
 SessionImpl::rollback()
 {
-	// Not an error to issue a ROLLBACK without a preceeding BEGIN
+	// Not an error to issue a ROLLBACK without a preceding BEGIN
 	_sessionHandle.rollback();
 }