[RFC 1/2] doc: update INSTALL to require GMime 3.0

[David Bremner]

This is the first step of removing support for pre 3.0 GMime.

This will allow us to spend less developement time ifdefing for
missing features in old GMime. It will also reduce the likelyhood of
bitrot in unused code paths.
---
 INSTALL | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/INSTALL b/INSTALL
index 6e6f4799..55c22167 100644
--- a/INSTALL
+++ b/INSTALL
@@ -20,7 +20,7 @@ configure stage.
 
 Dependencies
 ------------
-Notmuch depends on four libraries: Xapian, GMime 2.6,
+Notmuch depends on four libraries: Xapian, GMime,
 Talloc, and zlib which are each described below:
 
 	Xapian
@@ -46,6 +46,9 @@ Talloc, and zlib which are each described below:
 	Without GMime, Notmuch would not be able to extract and index
 	the actual text from email message encoded as BASE64, etc.
 
+        This version of Notmuch needs GMime no older than 3.0.0 (April
+        2017).
+
 	GMime is available from https://github.com/jstedfast/gmime
 
 	Talloc
@@ -95,7 +98,7 @@ dependencies with a single simple command line. For example:
 
   For Fedora and similar:
 
-	sudo yum install xapian-core-devel gmime-devel libtalloc-devel zlib-devel python3-sphinx texinfo info
+	sudo yum install xapian-core-devel gmime30-devel libtalloc-devel zlib-devel python3-sphinx texinfo info
 
 On other systems, a similar command can be used, but the details of
 the package names may be different.
-- 
2.17.0