Remove all composers who are 'Trad.' or 'Anon.'.

From now on, only put real people in the composer field.

Session/AllInAGardenGreen.abc

@@ -2,7 +2,6 @@ X:1015
 T:All in a Garden Green
 T:Harwood Hall
 R:March
-C:Trad.
 O:England
 Z:Paul Hardy's Session Tunebook 2013 (see www.paulhardy.net). Creative Commons cc by-nc-sa licenced.
 N: Change: GatheringPeascods.abc

Session/BearDance.abc

@@ -1,6 +1,5 @@
 X:1
 T:Bear Dance
-C: Trad.
 R:polka
 S: Nick Barber
 M:2/4

Session/BrightonCamp.abc

@@ -1,7 +1,6 @@
 X:1
 T:Brighton Camp
 T:The girl I left behind me
-C:Trad.
 O:England
 R:March
 Z:Transcribed by Bryan Creer

Session/EmmaFromFinland.abc

@@ -2,7 +2,6 @@ X: 1
 T: Emma From Finland
 M: 3/4
 L: 1/4
-C: Anon
 O: Finland
 K: FMaj
 D/F/ |: "Dm" A2 A | F D F | A2 A | F D D/F/ |

Session/GatheringPeascods.abc

@@ -1,7 +1,6 @@
 X:1
 T:Gathering Peascods
 M:C|
-C:Trad.
 S:Playford
 N:DM I: 1651-1690, transposed from A to G
 O:England

Session/GreenMountainPetronella.abc

@@ -1,7 +1,6 @@
 X:1
 T:Green Mountain Petronella
 S: Nick Barber
-C: Trad.
 O: Newfoundland
 R: Reel
 Q: 140

Session/HorsesBrawl.abc

@@ -2,7 +2,7 @@ X:1
 T:Horse's Brawl
 T:Le Bransle des Chevaux
 R:Reel
-C:From Arbeau, Orchesographie, 1689
+S:From Arbeau, Orchesographie, 1689
 O:France
 M:C|
 L:1/4

Session/LouthQuickstep.abc

@@ -1,7 +1,7 @@
 X: 1
 T: Louth Quickstep
-C: Joshua Gibbons MS
 O: Lincs
+S: Joshua Gibbons MS
 S: Peter D Sumner, Breakfast Publications, Grimsby
 M: 2/4
 K: G

Session/RiggedShip.abc

@@ -1,6 +1,5 @@
 X: 1
 T: Rigged Ship, The
-C: Trad.
 M: 6/8
 L: 1/8
 K: Gmaj

Session/SalmonTails.abc

@@ -1,7 +1,6 @@
 X:1
 T:Salmon Tails
 % Nottingham Music Database
-C:Trad.
 S:via PR
 M:4/4
 L:1/4

Session/ThemeVannetaise.abc

@@ -1,7 +1,6 @@
 X: 1
 T: Theme Vannetaise
 T: Twiglet
-C: Trad.
 O: Brittany
 M: 4/4
 K: G

Session/WillsWay.abc

@@ -1,6 +1,5 @@
 X: 1
 T: Will's Way
-C: Trad.
 N: Change: ThreeAroundThree.abc
 M: 4/4
 L: 1/8