Cleanup .gitignore

The .gitignore file contained ambiguous, duplicate and redundant entries.

.gitignore

@@ -7,6 +7,7 @@ coverage/**
 vendor/
 trident-installer.tar.gz
 trident
+!trident/
 *.pem
 *.csr
 docs/_build/
@@ -168,8 +169,6 @@ tramp
 
 # Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
 
-*.iml
-
 ## Directory-based project format:
 .idea/
 # if you remove the above rule, at least ignore the following:
@@ -223,8 +222,6 @@ fabric.properties
 # https://github.com/github/gitignore/blob/master/Global/Linux.gitignore
 ###############################################################################
 
-*~
-
 # temporary files which can be created if a process still has a handle open of a deleted file
 .fuse_hidden*
 
@@ -302,8 +299,6 @@ sftp-config.json
 *.un~
 Session.vim
 .netrwhist
-*~
-
 ###############################################################################
 # Windows
 # https://github.com/github/gitignore/blob/master/Global/Windows.gitignore
@@ -319,11 +314,5 @@ Desktop.ini
 # Recycle Bin used on file shares
 $RECYCLE.BIN/
 
-# Windows Installer files
-*.cab
-*.msi
-*.msm
-*.msp
-
 # Windows shortcuts
 *.lnk