add more test spreadsheets for libmwaw

Change-Id: I8810b84d2675ba3695578b5ed87c32dd1a686ae9
(cherry picked from commit e69f5861bbc21824bb10051c5326f6b0737e8f87)
add some test drawings/paintings for libmwaw

Change-Id: Id0f5aa7fbb92d15bbe877e85dd60b51107f49168
(cherry picked from commit 4828407311ccc68af67101c5b4b21828e8bebf7e)
add some test documents for libwps

Change-Id: I20aa49212b6ecbb819c9671b5c144f294653ab47
(cherry picked from commit 07123dc81558fbd21a7403f410ca326a457aca97)
move CppUnit plugin def. to separate source file

Change-Id: Id946419274728f96e1de41cffe84280e37e87ab3
(cherry picked from commit ccb51e13ed8602d4b394c99116a41e53a22403f2)
add convenience functions to handle dirs

Change-Id: I81c94565e09e0d839d95bf4f09b029838bb37ad5
(cherry picked from commit 31ba2cb2fcb3b9466c553cf12d50bc6437ee826f)
ensure writerperfect::DirectoryStream only works for dirs

Change-Id: I588d295d72a600710324ee936d0c2291872c1d73
(cherry picked from commit 72d7d1f33bcddaddb5f8589418d0b20f5433845d)
add unit test for writerperfect::DirectoryStream

Change-Id: I53aaf2355d9f3071544ebcaaee01bd44a30f88fc
(cherry picked from commit e98fbca5818bd60898f64fb41a16509239e09050)
add more test drawings/paintings for libmwaw

Change-Id: I7a85c7b7eae2abf29ff1a5742e1218346b1f9e00
(cherry picked from commit 8fd0320e8a890b559ec7c0b498c17e87a1a38ea5)