Use issue import API and other formatting improvements

[nicoddemus]

Hi,

Recently we migrated pytest from BitBucket and used your script, thanks for writing it and making it public!

I changed the requests to use the new import API because I was hitting the HTTP limit after migrating a few issues.

This PR includes a few other adjustments:

• Preserve the original date of creation for issues and comments (thanks to the new import API);
• Fix an encoding issue when a comment contains non-ascii characters;
• Change "Originally reported by" from footer to a header;
• Remove references to Hg changesets from comment bodies;
• Change explicit links in comments to relative links;
• When mentioning an user, add a link to its GitHub's profile as well;
• Add original kind and component as GitHub labels;

[yohanboniface]

Excellent :)

I used your fork to migrate uMap from bitbucket.
As I pushed to an organization while using my personal account, I needed this diff to have auth happy:

diff --git a/migrate.py b/migrate.py
index 29fb699..c997c18 100644
--- a/migrate.py
+++ b/migrate.py
@@ -210,7 +210,7 @@ def get_issues(bb_url, start_id):
     issues = []

     while True:
-        url = "{}/?start={}".format(
+        url = "{}/?start={}&count=50&sort=title".format(
             bb_url,
             start_id
         )
@@ -330,7 +330,7 @@ if __name__ == "__main__":

     # push them in GitHub (issues comments are fetched here)
     gh_username, gh_repository = options.github_repo.split('/')
-    auth = (gh_username, github_password)
+    auth = (options.github_username, github_password)

     # Sort issues, to sync issue numbers on freshly created GitHub projects.
     # Note: not memory efficient, could use too much memory on large projects.

I also needed the sort + count change, otherwise only 180 of the 201 issues were migrated, dunno why.
For the record, the command line I used:

python migrate.py yohanboniface umap yohanboniface umap-project/umap

[nicoddemus]

Cool, thanks for sharing! 😄

[jeffwidman]

@vbabiy any reason this isn't merged?

[jeffwidman]

@vbabiy was nice enough to pass along the repo to me for continuing maintenance, so I've gone ahead and merged this--thanks again @nicoddemus (and a huge thank you from me for your work on pytest, I use it all the time.)

[jeffwidman]

I fixed the auth problem for pushing to a Github organization a little more cleanly in de04454

Also I suspect/hope #30 will fix the issue with count/sort params being required in the BB url.

[nicoddemus]

@jeffwidman nice, thanks for taking over this repo!

and a huge thank you from me for your work on pytest, I use it all the time.

Cool, thanks for the support! 😄