[pitivi] Fix some typos

[Piotr Drąg <piotrdrag src gnome org>]

commit 1e6257a00bffbcff0da39cd873db33927b0ebc0d
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Sat Jan 23 18:15:32 2016 +0100

    Fix some typos

 data/ui/renderingdialog.ui |    2 +-
 pitivi/medialibrary.py     |    8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/data/ui/renderingdialog.ui b/data/ui/renderingdialog.ui
index 2a76dc5..ba974f6 100644
--- a/data/ui/renderingdialog.ui
+++ b/data/ui/renderingdialog.ui
@@ -791,7 +791,7 @@ This option is a good trade of between quality of the rendered video and stabili
                     <property name="visible">True</property>
                     <property name="can_focus">True</property>
                     <property name="receives_default">False</property>
-                    <property name="tooltip_markup" translatable="yes">Always use source assets for 
rendering. It is the best choice for the quality of the redered video , but you might hit some bugs because 
of the use of not officially supported media formats.
+                    <property name="tooltip_markup" translatable="yes">Always use source assets for 
rendering. It is the best choice for the quality of the rendered video, but you might hit some bugs because 
of the use of not officially supported media formats.
 &lt;i&gt;Use at your own risk!&lt;/i&gt;</property>
                     <property name="xalign">0</property>
                     <property name="yalign">0</property>
diff --git a/pitivi/medialibrary.py b/pitivi/medialibrary.py
index a1d9594..dffd98e 100644
--- a/pitivi/medialibrary.py
+++ b/pitivi/medialibrary.py
@@ -125,12 +125,12 @@ class FileChooserExtraWidget(Gtk.Grid, Loggable):
         self.__automatic_proxies = Gtk.RadioButton.new_with_label(
             None, _("Create proxies when the media format is not supported officially"))
         self.__automatic_proxies.set_tooltip_markup(
-            _("Let Pitivi decide when to "
+            _("Let Pitivi decide when to"
               " create proxy files and when not. The decision will be made"
               " depending on the file format, and how well it is supported."
-              " For example H264, FLAC files contained in Quicktime will"
-              " not be proxied, but AAC, H264 contained in MPEG-TS will.\n\n"
-              " <i>This is the only option officially supported by the"
+              " For example H.264, FLAC files contained in QuickTime will"
+              " not be proxied, but AAC, H.264 contained in MPEG-TS will.\n\n"
+              "<i>This is the only option officially supported by the"
               " Pitivi developers and thus is the safest."
               "</i>"))