minor wording/spelling changes

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@19864 b3059339-0415-0410-9bf9-f77b7e298cf2

DOCS/tech/slave.txt

@@ -144,8 +144,8 @@ grab_frames
 
 screenshot <value>
     Take a screenshot. Requires the screenshot filter to be loaded.
-        0 take a single screenshot
-        1 start/stop taking screenshots with each frame
+        0 Take a single screenshot.
+        1 Start/stop taking screenshot of each frame.
 
 gui_[about|loadfile|loadsubtitle|play|playlist|preferences|skinbrowser|stop]
     GUI actions
@@ -237,7 +237,7 @@ seek_chapter <value> [type]
         1 is a seek to chapter <value>.
 
 set_mouse_pos <x> <y>
-    Sets the coordinates of the mouse on the screen.
+    Set the coordinates of the mouse on the screen.
 
 set_property <property> <value>
     Set a property.