fdo#72031 RTF import: bogus call to getBestTextEncodingFromLocale()

There were two problems here. First, commit
bbe3627eece0c3486e7ea11f2f13377aaa3a8fed (rtftok: stop sending
sprm:CRgFtc{0,1,2} tokens, 2014-03-05) broke the use-case when the font
encoding is 0, but it's present. Before that commit, we parsed the font
encoding instantly; after that commit we parse it once we have a font
name. If we do that, then we have to have an idea if we have a font
encoding. Given that 0 is a valid encoding, use -1 for the "have no
encoding" case instead.

Second, commit 7839633fb356285652ed96f4bf3f85bcd5b561a4 (fdo#85889
handle pc, pca and mac rtf keywords in writerfilter, 2014-11-24) abused
m_nCurrentEncoding, which is meant to be used within the font table
only. The problem with this is that this way only the first font will
get the encoding, while the spec says it should be used in every context
where there is no other explicit encoding. Fix this by setting the
default encoding for those 3 control words instead -- and consider the
default encoding in getEncoding().

Change-Id: Ia1d71f8ce70f2a53a3770b4840e21362d082e71f
writerfilter: turn RTFOverwrite into a C++11 scoped enumeration

Change-Id: Ic49033c85f77be8ba415078ae5e3518ef0faae75
writerfilter: only dmapper needs TableManager.hxx

Change-Id: I3354f82a3dd0a598b5405ab32c5d1b0d370829c3
Unused writerfilter::TagLogger::propertySet

Change-Id: If0dd607823cad5dbc2da2df93ed0847a34791b58
TableManager is only used with PropertiesPointer=TablePropertyMapPtr

Change-Id: Ie036cafd769328d9d5cc42265534ed8f7c0d0f2c
Avoid having TableManager as a template class

It was always used with T=css::uno::Reference<css::text::XTextRange>

Change-Id: If79413cf68ad5d5f6fc7aba1c065f49e5781d71d