DOCX Input: Add support for contextual spacing

DOCX Input: Add support for the Word setting "No space between
paragraphs with the same style". Fixes #1191001 [docx conversion bug](https://bugs.launchpad.net/calibre/+bug/1191001)

src/calibre/ebooks/docx/styles.py

@@ -260,6 +260,7 @@ class Styles(object):
             for attr in ans.all_properties:
                 if not (is_numbering and attr == 'text_indent'):  # skip text-indent for lists
                     setattr(ans, attr, self.para_val(parent_styles, direct_formatting, attr))
+            ans.linked_style = direct_formatting.linked_style
         return ans
 
     def resolve_run(self, r):
@@ -389,6 +390,19 @@ class Styles(object):
                 else:
                     ps.numbering = (ps.numbering[0], lvl)
 
+    def apply_contextual_spacing(self, paras):
+        last_para = None
+        for p in paras:
+            if last_para is not None:
+                ls = self.resolve_paragraph(last_para)
+                ps = self.resolve_paragraph(p)
+                if ls.linked_style is not None and ls.linked_style == ps.linked_style:
+                    if ls.contextualSpacing:
+                        ls.margin_bottom = 0
+                    if ps.contextualSpacing:
+                        ps.margin_top = 0
+            last_para = p
+
     def register(self, css, prefix):
         h = hash(frozenset(css.iteritems()))
         ans, _ = self.classes.get(h, (None, None))

src/calibre/ebooks/docx/to_html.py

@@ -86,6 +86,7 @@ class Convert(object):
         self.framed_map = {}
         self.anchor_map = {}
         self.link_map = defaultdict(list)
+        paras = []
 
         self.log.debug('Converting Word markup to HTML')
         self.read_page_properties(doc)
@@ -94,6 +95,8 @@ class Convert(object):
             if wp.tag.endswith('}p'):
                 p = self.convert_p(wp)
                 self.body.append(p)
+                paras.append(wp)
+        self.styles.apply_contextual_spacing(paras)
 
         notes_header = None
         if self.footnotes.has_notes:
@@ -107,12 +110,16 @@ class Convert(object):
                 dl.append(DT('[', A('←' + text, href='#back_%s' % anchor, title=text), id=anchor))
                 dl[-1][0].tail = ']'
                 dl.append(DD())
+                paras = []
                 for wp in note:
                     if wp.tag.endswith('}tbl'):
                         self.tables.register(wp, self.styles)
                         self.page_map[wp] = self.current_page
+                    else:
                         p = self.convert_p(wp)
                         dl[-1].append(p)
+                        paras.append(wp)
+                self.styles.apply_contextual_spacing(paras)
 
         self.resolve_links(relationships_by_id)