Match correct column for lines w/ multibyte chars

When matching columns with vim regexps (\%c), it matches the byte
column, not the display column. This requires that any matches on lines
with multibyte characters compensates for the added byte length of the
multibyte characters. This commit contains a fix for this issue.

Closes #28.

plugin/EasyMotion.vim

@@ -369,6 +369,7 @@
 			" Dict structure:
 			" 1,2 : a
 			" 2,3 : b
+			let sort_list = []
 			let coord_keys = {}
 			let group_key = a:0 == 1 ? a:1 : ''
 
@@ -377,16 +378,29 @@
 
 				if type(item) == 3
 					" Destination coords
-					let coord_keys[join(item, ',')] = key
+
+					" The key needs to be zero-padded in order to
+					" sort correctly
+					let dict_key = printf('%05d,%05d', item[0], item[1])
+					let coord_keys[dict_key] = key
+
+					" We need a sorting list to loop correctly in
+					" PromptUser, dicts are unsorted
+					call add(sort_list, dict_key)
 				else
 					" Item is a dict (has children)
-					call extend(coord_keys, s:CreateCoordKeyDict(item, key))
+					let coord_key_dict = s:CreateCoordKeyDict(item, key)
+
+					" Make sure to extend both the sort list and the
+					" coord key dict
+					call extend(sort_list, coord_key_dict[0])
+					call extend(coord_keys, coord_key_dict[1])
 				endif
 
 				unlet item
 			endfor
 
-			return coord_keys
+			return [sort_list, coord_keys]
 		endfunction
 	" }}}
 " }}}
@@ -404,17 +418,35 @@
 		" Prepare marker lines {{{
 			let lines = {}
 			let hl_coords = []
+			let coord_key_dict = s:CreateCoordKeyDict(a:groups)
+
+			for dict_key in sort(coord_key_dict[0])
+				let target_key = coord_key_dict[1][dict_key]
+				let [line_num, col_num] = split(dict_key, ',')
 
-			for [coords, target_key] in items(s:CreateCoordKeyDict(a:groups))
-				let [line_num, col_num] = split(coords, ',')
+				let line_num = str2nr(line_num)
+				let col_num = str2nr(col_num)
 
 				" Add original line and marker line
 				if ! has_key(lines, line_num)
 					let current_line = getline(line_num)
 
-					let lines[line_num] = { 'orig': current_line, 'marker': current_line }
+					let lines[line_num] = { 'orig': current_line, 'marker': current_line, 'mb_compensation': 0 }
 				endif
 
+				" Compensate for byte difference between marker
+				" character and target character
+				"
+				" This has to be done in order to match the correct
+				" column; \%c matches the byte column and not display
+				" column.
+				let target_char_len = strlen(matchstr(lines[line_num]['marker'], '\%' . col_num . 'c.'))
+				let target_key_len = strlen(target_key)
+
+				" Solve multibyte issues by matching the byte column
+				" number instead of the visual column
+				let col_num -= lines[line_num]['mb_compensation']
+
 				if strlen(lines[line_num]['marker']) > 0
 					" Substitute marker character if line length > 0
 					let lines[line_num]['marker'] = substitute(lines[line_num]['marker'], '\%' . col_num . 'c.', target_key, '')
@@ -425,6 +457,10 @@
 
 				" Add highlighting coordinates
 				call add(hl_coords, '\%' . line_num . 'l\%' . col_num . 'c')
+
+				" Add marker/target lenght difference for multibyte
+				" compensation
+				let lines[line_num]['mb_compensation'] += (target_char_len - target_key_len)
 			endfor
 
 			let lines_items = items(lines)
@@ -489,6 +525,7 @@
 				call s:VarReset('&modifiable', 1)
 				call s:VarReset('&readonly', 0)
 				call s:VarReset('&spell', 0)
+				call s:VarReset('&virtualedit', '')
 			" }}}
 			" Find motion targets {{{
 				let search_direction = (a:direction == 1 ? 'b' : '')
@@ -580,6 +617,7 @@
 				call s:VarReset('&modifiable')
 				call s:VarReset('&readonly')
 				call s:VarReset('&spell')
+				call s:VarReset('&virtualedit')
 			" }}}
 			" Remove shading {{{
 				if g:EasyMotion_do_shade && exists('shade_hl_id')